In frame one, Charlie Brown is shuffling along, baseball cap peak drooping to the ground. “When you lose the first game of the season,” he says, “it’s a long walk home.” Frame two, he sees a rock: “If anything gets in your way, you just want to kick it!” Frame three, he swipes hopelessly with his foot at the rock, misses and falls over. The moral is in the fourth frame, as Charlie continues his lugubrious shuffle: “Then you discover you can’t even kick good.”

As a child, I loved Charles M Schulz for comic strips such as this. In four frames he told truths that every child knows but too often go unrecognised when adults write for kids: namely, that life is difficult, one’s shortcomings feel insuperable and that, when fate has laid you low, it comes along to kick you again in the proverbials.

For adults, the only certainties in life were death and taxes. For kids like me and Charlie Brown there was a third one – our constant companion is, and will always be, worry. “Sometimes you lie in bed and you don’t have a single thing to worry about,” Charlie Brown reflected once. “That always worries me.”

I loved Charlie Brown for his insecurity, for admitting that he was unfit for the game of life, for providing consolation in a literary world of supposed role models. Here, at last, was a kindred spirit, one who served as a rebuke to pretty much every other character in books or TV shows I came across as a kid. Enid Blyton’s Famous Five, for instance, were always overcoming adversity; Charlie Brown was endlessly defeated by it. The Five were forever exposing adult crime rings, taking ludicrous, healthy dips in early springtime ponds and eating seven square meals a day. Charlie Brown was, like me, too full of self-doubt and torment to be part of the Blyton gang.

It took him to show me what I knew already, that childhood involves not only failure but an inability to overcome failure, and for that I shall be eternally grateful.

I have a photo from the early 1970s that has mystified me for decades. It shows me in the Alder Coppice junior school football team which has just won the Dudley under-11s six-a-side trophy. But how could I have been in that team when I kicked like Charlie Brown? Perhaps the trophy – or me – were pasted in using an early version of Photoshop. Those are the only possibilities that make sense. Je suis Charlie (Brown). One reason Peanuts endured from 1950 to 2000, and was published in more than 2,600 newspapers in 75 countries and 21 languages, reaching a global audience of 355 million, was that all 17,897 of the four-framed comic strips that bore the name were drawn by that rare thing – an adult who didn’t want to systematically airbrush what childhood was really like.

“I don’t think it was a calculated strategy to shatter the idyllic perceptions of childhood,” Schulz’s widow, Jean, told me recently. Her husband died 15 years ago and, for reasons we needn’t get into, she calls him Sparky.

“Sparky said many times that he observed that there was a whole world going on in the playground that adults had no clue about. I think Sparky intensely held on to the feelings he had, whereas many of us discuss them with our parents or others and then let them go.”

Although Schulz spent much of his life in sunny California, he set Peanuts in the Minnesotan landscape of his youth. For me, that setting added to the melancholy mood, particularly when – as always seemed to be the case when I watched the TV versions – the action unfolded in winter. To my childhood ears, it sounded as though all the voiceover artists had colds, which made the characters seem sadder and made Peanuts seem not so much cartoon as lugubrious dramatic exploration of seasonal affective disorder.

Perhaps the Scandinavians, who settled in the part of the US in which Schulz grew up, brought their northern European angst with them. Certainly, Ibsen and Strindberg made a lot of sense to me as an adult because I was raised on Peanuts. Even now, if I look at Munch’s The Scream I can imagine what Charlie Brown would have looked like had he ever grown up – bald, wizened and existentially demented through worry. Just as well he never did grow up.

I also loved Charlie Brown because he never got the Little Red-Headed Girl. He always wanted to, but never quite could, make the first move: “I hate myself for not having enough nerve to talk to her,” he said in one strip. “Well, that’s not exactly true … I hate myself for a lot of other reasons too.”

Better yet, he only knew hopeless ways to try to attract her. “I should take this bottle cap over to that Little Red-Headed Girl,” Charlie said once. “If she has a bottle cap collection, she’ll throw her arms around me and say, ‘Thank you! Thank you! Thank you!’”

Oh, Charlie! That’s never going to work.

This resonated for me as a small boy. I didn’t get the girl either. I still remember putting the moves on a fellow primary schooler in a Shropshire beer garden one summer’s evening in the early 70s. Within seconds, I was pinned down on the grass by my alpha male rival, the publican’s burly son. In between thumps to the face, I glimpsed the girl smiling and egging him on and instantly learned a valuable life lesson: three is never a crowd; triangulation often helps to inflame desire. Then my mother came out of the pub and told me to stop fighting. I wasn’t, mother. I was getting beaten up.

In such a world, which is the real world of childhood, with its miseries, beatings and unattainable girls, Charlie Brown was a solace. At least one person in it knew what suffering was like even if he was a small American with an oversized head, cowlick forelock and a voice that sounded as though he had a permanent cold. “I think the comic strips carry simple truths,” says Jeannie Schulz. “It is a mixed world out there – sometimes sweet, sometimes joyous and sometimes disappointing. Disappointments are often sharp and stick with us a long time. Someone once said to me that Peanuts teaches us how to be human. I thought that was pretty profound.”

All the foregoing leads me to worry about the new Peanuts movie that will be released here next month. Director Steve Martino recently explained what it will be about. “Here’s where I lean thematically,” he said. “ I want to go through this journey … Charlie Brown is that guy who, in the face of repeated failure, picks himself back up and tries again … I think what Charlie Brown is –what I hope to show in this film – is the everyday qualities of perseverance … to pick yourself back up with a positive attitude – that’s every bit as heroic … as having a star on the Walk of Fame or being a star on Broadway.”

Perseverance? Positive attitude? The Chumbawumba I-get-knocked-down-I-get-back-up-again philosophy? That’s not Charlie Brown. I don’t want to be too sceptical because The Peanuts movie director is clearly a genius when it comes to adapting much loved childhood stories (Martino adapted Dr Seuss’s Horton Hears a Who! which is obviously a masterpiece) and because I haven’t seen the results yet, but he seems to be confusing Charlie Brown with another Peanuts character. Perseverance, you see, was never Charlie Brown’s forte, more Schroeder’s.

You remember Schroeder. He always had his nose hanging over the piano keyboard, lost in concentration. As psychologist James C Kaufman says of Schroeder: “Disciplined and focused on his passion for classical music, one can imagine him setting his alarm clock for 7am on weekends to try [Beethoven] one more time.”

If you wanted someone to overcome adversity, Schroeder was your go-to guy, not Charlie Brown.

Indeed, Schroeder demonstrates one of the five character types that Kaufman, professor of psychology at California State University at San Bernardino, set out in what he calls his Charlie Brown Theory of Personality. According to this, Charlie Brown is a model neurotic (this possibly explains why he can’t fly a kite), Snoopy is an extrovert (that’s why he sleeps on rather than in his kennel), Lucy personifies disagreeableness (bossy and opinionated, she bullies her brother Linus and Charlie Brown), the adorable, comfort-blanket clutching poppet Linus is open to new experiences (that’s why in the 1968 TV special, he spends Halloween waiting in the pumpkin patch, believing that the Great Pumpkin will come like some October version of Father Christmas, even though his chums are filled with charmless Dawkins-like scepticism), while Schroeder is the Conscientious type.

This is a superb account of the human psyche as far as it goes – even if it is just an application to Peanuts of the well-known Five Factor Model of human psychological traits.

But Kaufman’s Charlie Brown theory doesn’t go far enough. There are more than five character types in Peanuts, and, intriguingly, each is a manifestation of aspects of Charles M Schulz’s personality. Jeannie Schulz explains: “Sparky used to say, ‘I’m a little bit of all of the characters. Charlie Brown is my wishy-washy and insecure side. Lucy is my smart alec side. Linus is my more curious and thoughtful side. Snoopy is the way I would l like to be – fearless, the life of the party, and brushing off Lucy’s bad temper with a glancing kiss.’ Sally expressed Sparky’s exasperation with things in this world: school trips, the difficulties of mastering the television controls. Woodstock is his easygoing, just wants to be a friend, side.”

“Schulz was all the characters in Peanuts,” says Diary of a Wimpy Kid creator Jeff Kinney in a new book celebrating the 65th anniversary of Peanuts called Only What’s Necessary: Charles M Schulz and the Art of Peanuts. “Each character represented a different aspect of Schulz, making Peanuts perhaps the most richly layered autobiography of all time.”

Kinney compares Schulz to Shakespeare. In creating Macbeth, “Shakespeare embodied a single character with a full and often contradictory range of human traits – ambition, weakness, gullibility, bravery, fearfulness, tyranny, kindness.” Schulz’s genius, argues Kinney, was to put these traits in different characters rather than one, and to bring them to life with a few economical strokes of his pen.

“I hope the strip is relevant to children today,” says Jeannie Schulz. I think children come to the characters each in his or her own way.”

Let’s hope. For all the psychological richness of Peanuts, it’s one character who remains a touchstone for me – Charlie Brown, the boy whom Kaufman rightly points out is prone to “depression and anxiety and paralysing fits of over-analysis”. Mon semblable! Mon frère!

Let’s finish then by remembering Charlie Brown in a 1988 strip, proto-stalking the Little Red-Headed girl, in an eternal winter of frustrated desire in which the fates conspire to bite him repeatedly on the bum. Frame one: he’s half-hiding behind a tree, clutching the trunk with both hands. “There’s the house where the Little Red-Haired Girl lives.” Frame two: Maybe if I stand here long enough, she’ll come out.” Frame three: “She doesn’t know that I could stand here for hours.” Frame four: “I have to … because my mittens are frozen to the tree.”

Only What’s Necessary: Charles M Shultz and the Art of Peanuts is out now. The Peanuts Movie is released in the UK on 21 December