So, this is my little den,” the poet Michael Rosen says, showing me into his north London office. The den brims. Books fill shelves. Boxes pile on other boxes. Knickknacks freckle a desk. “Where would you like to sit?” he goes on. I choose the only seat he isn’t about to occupy himself, something wooden and old and half-covered by a coat. Rosen describes it as a “captain’s armchair” and seems satisfied. “It was my dad’s,” he says. Then a mischievous grin appears, as though he knows what is about to happen. When I sit down, the chair groans under my weight, and I become scared to move in case it gives way. Rosen says, plainly, “It’s a bit creaky.”

Rosen is the author of 140 books of poetry and prose, and is our former Children’s Laureate. He is tall and lanky; when he sits down at his desk it is like watching a long piece of paper fold itself into creases. It’s more than two years since he left hospital after a near-lethal battle with Covid. And though while in hospital nurses shaved his jaw clean, now his beard has returned and so has his good humour, so that he more closely resembles the Rosen people know: scruffy, daffy, softly playful.

“How are you?” I say, to begin.

“I’m OK,” he says. “The eye bothers me.”

Since Covid, the vision in Rosen’s left eye has been impaired. His left ear is what he describes as “a dead loss”. Every now and then he will experience a sudden shooting pain that chases itself around his body – one moment it’s in the knee, then the shoulder, then the hip. (“Boing!” he says, “and it’s moved on.”) It has taken Rosen until recently to feel accepting of this new physical state. The body changes, he says, and the brain must catch up. Still, he seems sanguine about it all, particularly the eye. “I could wear a patch and it would be much better,” he says. “But do I want to walk around wearing a patch?” He shakes his head, thinking of the schoolchildren he sometimes reads his poems to. “I don’t fancy it.”

Rosen and I are meeting to discuss Getting Better, his new memoir, in which he describes, often in forensic detail, some of his life’s most fraught experiences, and explains the ways in which he’s made it to 76 years old. There is a chapter on Covid. Another on the premature loss of his mother. Another still on the discovery of an elder brother, Alan, who died before Rosen was born. Reading several chapters in quick succession will invite you to question how Rosen has coped. He provides some answers – often they are witty. But still you wonder. And that is before you read the passages that cover the central catastrophe of Rosen’s life, the death of his 18-year-old son, Eddie, from meningococcal septicaemia, in 1999.

I notice on Rosen’s desk an unframed photograph of a young man. Rosen swivels to look. “That’s him,” he says, “not all that long before he died.”

The man in the photograph is thickset and beautiful in a chequered shirt, holding something to his mouth.

I ask, “How old was he then?”

“I should think about 17,” Rosen says. “I think he’s chewing some straw. He was always chewing something, or flicking something…” He briefly narrows his eyes. “Well, there you go.”

Though Rosen has written about Eddie’s death previously (specifically in Michael Rosen’s Sad Book, a children’s title that begins with the words “This is me being sad,” beneath a Quentin Blake illustration of Rosen grinning), he has only done so sparingly and never in great detail. In Getting Better, he lays out the detail. One night Eddie complained of a headache. The next morning Rosen discovered his body cold and unmoving. When a 999 operator advised Rosen to remove Eddie from bed and place him on the floor in the recovery position – Rosen by this point knowing but not knowing that his son was already gone – Eddie fell stiffly and out of his mouth came “a bit of pale red fluid,” he writes. Paramedics confirmed Eddie’s death at the scene. Rosen watched them slide his son downstairs in a body bag. In the book, he recalls the terrible sound of the bag being zipped closed.

Soon after Eddie’s death, Rosen and Eddie’s mother, his first wife, travelled to Paris to get away. Walking through a cemetery one day, they encountered a woman crying at the foot of her young son’s grave and struck up a conversation. “It was an incredible moment,” Rosen says. “On the one hand, I felt terrible for her. On the other I was thinking, I don’t think I can live like that, I must find ways to be less incapacitated. I actually had those feelings. Most people who are grieving, they quite often have those thoughts – that they must find a way to carry on. It’s whether you succeed in doing it. It’s an effort. It’s quite a thing to do.”

It has now been 23 years since Eddie’s death. For the most part, Rosen has succeeded in escaping incapacitation. “I’ve tried not to be burdened by it,” he says. “I talk in the book about ‘carrying the elephant’.” Rosen hands me a postcard replica of an engraving of a man struggling to carry an elephant up a hill. “I bought that in Paris,” he goes on, “and it’s a great reminder. You know, I’m not carrying an elephant. At the time I thought I was. Eddie’s dead and I’m carrying all this grief and it’s bigger than me – it’s as big as an elephant. But not any more. Even with this Covid thing, or with any of that other stuff, I’m still not carrying an elephant. So this picture, it inspires me.”

“It inspires you?” I repeat.

“Because I’m not him!” Rosen says. “So you try not to be burdened?” I ask. “Or not to be a burden?” “Both, actually,” he says. “I guess I have sad thoughts every day. But I try not to be overcome by them.”

In Getting Better, Rosen implies that coping is an everyday practice – we are coping even when we are unaware we are coping, and perhaps especially in those moments. Partway through our conversation I ask Rosen, “How have you coped?” hoping he might share some strategies, though he misunderstands the question.

“I’ll give myself a mark, shall I?” he says. “Right, fair enough. No, I think this is quite a good thing to do actually. Like they did at the Beeb. Every now and then you have to do a little…”

“An appraisal,” I say.

“That’s right, an appraisal. ‘So, how have you coped, Michael? What mark would you give yourself? Are you worth a bonus?’ Well, there are times when I do pat myself on the back. I’ll say, ‘Well done, you coped with that, you’ve done all right.’ But in the great run of things, was it so tough? Given what I’ve been through, I’ve done OK. If you were to mark it in terms of difficulty, I’m about a five. Whereas other people are dealing with nines.”

When I ask Rosen if he would have written this book had he not almost lost his life to Covid, he says, “Probably not. No.” Becoming perilously unwell – “poorly,” as the doctors described it, as though he had a mild cold – has brought to the surface several other troubling periods in his life. “Freud’s got a word for it,” he says. “What does he call it – condensation? When one thing happens and you pour into it all your feelings from other places?” As Rosen was feeling “sad about being ill and being feeble it sort of drew in, like a vacuum cleaner, all this other stuff.”

I wonder aloud why he has never previously told the story of Eddie’s death.

“Probably because I didn’t want to sit anybody down and say, ‘Can I tell you all of this?’,” he says. “I chewed it over with my dad and step-mum at the time. They lived it. We talked our way through it. But that was back in 1999. And I haven’t done it again.” He thinks for a moment. “There’s a way sometimes when writing is a bit like gathering up some stuff and getting it into one place… I hadn’t actually put it all together in one place.”

“When you put it all down together,” I say, “the amount of loss, I hadn’t appreciated…”

“Neither had I,” says Rosen.

“It’s astonishing,” I say.

“Quite,” he says. “Of course, it’s not the totality, is it? What about all the other things I do, the mucking about, the performing? They’re not in the book. You might read it and think of me as a person in the pool of glum. But when you pull it all together… In an absurd way it’s funny. What else is going to happen? Is the house going to burn down?”

Rosen’s greatest coping method might be his tendency towards rigorous self-understanding; writing the book has been a way for him to process events. “One thing I say to kids is, ‘If you think of a thought as a ping-pong ball in your head – your head’s empty, and there’s a ping-pong ball bouncing around in there like it’s in a bottle, bing-bong, bing-bong – well, can you get the ping-pong ball outside your head so that it’s not making all of that noise?”

I ask, “Is your ping-pong ball out?”

“Yes,” he says.

“Did it need to come out?” I ask.

“Yes,” he nods, and goes on, “I don’t know how other people describe bereavement, but I always think of the thoughts as swirling, a bit swirly-whirly.”

“They’ve been swirly-whirly for 20 years?” I ask.

“Oh, yes,” he says. “And I can still have swirly-whirly moments. Absolutely. I had one just the other day.” Rosen still dreams of Eddie vividly. “So when I wake up there is a moment a bit like a sort of mini-bereavement,” he says. “You’re there and he’s there and you’re living with him. And then you wake up and realise you can’t be with him… And then there’s these other dreams where he knows he’s going to die. He says things about it, that he knows he’s ill. I think that’s strange. The mind plays me a video of Eddie and puts over it a soundtrack I’ve created of his voice, as if I’ve written him a script, in which he says, ‘I think I’m going to die, Dad.’”

I ask, “Is it always the same dream?”

“No,” he says. “It’s different. Sometimes he’s wearing clothes I’ve forgotten about, so I wake up and go, ‘Oh my God, I remember that shirt!’”

After the dreams, Rosen feels sadness for a few minutes, but then there are cats to feed and schoolchildren to read to and tweets to conjure and books to write. “I’m a great believer in these small practical tasks,” he says. “The fact that you would go to a shop and buy some loo roll and come home, I get immense satisfaction from these things. They’re about getting on, achieving things. It’s completely absurd, isn’t it? It’s completely trivial.” Time is not a healer, in Rosen’s mind, but doing things is. “Think of all the things I’ve done between 1999 and now,” he says. “Well, to a certain extent they displace some of the grief, though you can’t escape it.” He adds, “For people who lose somebody, with very long days to get through and very little to do, I think that’s difficult. They talk about the talking cure. Well, there is a sort of doing cure, too.”

In Getting Better, Rosen describes the moment he discovered a photograph of a baby boy sitting on his mother’s knee. When he asked his father who the boy was, Rosen or his older brother, Brian, his father said neither – that it was a third son, Alan, who had died as an infant, before Rosen was born. Rosen was 10 at the time. Nobody in his family had spoken of Alan previously, there were no photographs of him in the house. And though Rosen’s father, Harold, mentioned Alan from time to time over the course of his life, Rosen never spoke about him with his mother, Connie.

“It’s bewildering,” Rosen says, when I ask about his parents’ response. “It’s in the book, really, because I’m looking at how they coped with that trauma.” Rosen grew up in a flat in Pinner, northwest London; both of his parents were teachers. He describes his mother as “in many ways extraordinary”. Of her refusal to discuss Alan, he says, “It’s incredibly gutsy, but at the same time quite worrying that she thought she couldn’t, or shouldn’t, mention it.” Rosen never quizzed his mother on the issue; she died at 56. “She wasn’t a hard woman. She was the soft one, hardly ever got angry with us, whereas the old man sometimes lost his rag. But there must have been some inner grit to make that decision. We would now think that it’s not a great idea – the general consensus seems to be, ‘OK, you don’t have to let it all hang out, but you can say it, you can talk about it.”

In Rosen’s thinking, talking about it, writing about it – it all helps. (Expel the ping-pong ball and regain agency!) Though in some ways his mother’s approach lingers in him. Eddie is buried in Highgate Cemetery, but Rosen doesn’t visit the grave. And he finds it troubling to watch videos of his son. “He did drama in the sixth form,” Rosen says near the end of our conversation, “and he’s in a video of one of the plays he wrote. I’ve never looked at it. I don’t think I can. He was wearing a helmet. It’s in that box.”

He points to a cardboard box on which is scrawled the word HELMET, and I wonder what else of Eddie might be crammed into this den, out of sight.

“I remember saying to him afterwards, ‘Why did you wear that?” And he said, ‘Well, I don’t know.’”

He shrugs playfully – the memory isn’t a bad one. It vibrates with all the others he has.

I ask him about the grave.

“I thought the other day I should visit,” he says. “I ought to. People say they go and see it.” He turns to his desk, picks up a piece of white card that is folded in half, and hands it to me. “I’ve even got the guide here,” he adds. “In case I ever do.”

Getting Better by Michael Rosen (Ebury, £16.99). To support The Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply.