A decade and a half ago, in the middle of what was then an unusually hot English summer, I found myself lying on the loft floor of a detached 1930s house on the outskirts of Whitstable while a bailiff in full body armour knelt on my chest and threatened to kill me.

He knew where I lived, he said; he'd come and find me or my family and wait until it was dark and I didn't have anyone with me and then he would fucking kill me. His face was inches from mine as he shouted all this, and his sweat was dripping on to me, and with his weight on my chest I could hardly breathe. His colleagues pulled him away, taking off his helmet and gloves and splashing his face with water, telling him to calm down. They dragged me across the loft – I'm not sure whether I refused to stand or was simply too shocked to do so – and lowered me through the hole they'd made into the room below.

From there I could see through the window to the meadow opposite, where two parallel lines of white survey posts traced the route of a planned bypass road – a route which came in through the front door of the house and crashed out through the back, passing the security compound a few hundred yards beyond and rolling down through already abandoned agricultural fields, a copse of oak trees, a larger woodland, more meadows, a golf course and an open area of scrubland before rejoining the main coastal road some seven or eight miles away.

I was pushed out through the window, down a ladder, and escorted away from the house. I stood in the meadow, caught my breath, and turned to watch my fellow protesters being taken down from the roof before the house was pulled to the ground.

I blame the Guardian. Specifically, I blame CJ Stone's Housing Benefit Hill column, which was then running on Saturdays, and a line from that column which read: "Our town already has a bypass. So they're going to build another one. Which makes the second bypass a bypass to bypass a bypass... to save a possible two minutes' travelling time in the rush to get from here to there."

This was not only enough to persuade me to join an anti-road protest; it also made me want to become a writer. See what a couple of good sentences can do?

I was 19 at the time, on a long summer break between my first and second years at university, filled with righteous anger about world politics, the environment, the encroaching police state and the price of cigarettes. I hitchhiked from Norfolk down to Kent (that's right, irony fans; I travelled by car to a road protest), arriving late one evening in the first week of July. I was welcomed, fed, shown somewhere to sleep, and by lunchtime the following day I was wedged under a bulldozer and in danger of being arrested for the newly created offence of aggravated trespass.

I wasn't arrested that day, or any other day. We waited for the police to arrive, and when they did we ran away into the woodland which bordered the construction site. Avoiding arrest – an easily avoided and time-wasting indulgence – turned out to be one of the rules of the group. There was also a no-violence rule, a no-drinking rule, and a ban on the sitting around and day-dreaming, which was known as yogurt weaving. Wind chimes and bongos were also verboten.

The no-drinking rule was a surprise – I was told it had been brought in after a few "incidents and problems" – but undoubtedly made for a focused group which was able to concentrate on protest actions: mornings started early, nights were spent cutting fences, arguments were made briefer by being conducted with clear heads. That the rule was kept to was an even greater surprise, although possibly helped by the fact that no one had any money. (The no-drinking wasn't a problem for me; I was partway through a three-year abstinence which had been brought on by a few "incidents and problems" of my own.)

Sometimes, for all its anger and heartfelt argument, the direct action against the road building felt like a game. The security guards, temporary agency workers from the local area with little training, were paid whether or not we managed to interrupt the work. The contractors actually had an interest in the job taking longer, and would often turn their engines off as soon as they saw us, reaching for a thermos flask and a newspaper. It wasn't always friendly, though. The guards had the right to remove us using "reasonable force", and some of them interpreted this more enthusiastically than others. Similarly, some of the protesters raised the stakes unnecessarily: one man would scream "EARTH RAPIST!" at almost everyone he came into contact with; another, who was later eased out of the group, used a catapult and ball bearings to attack the security compound. Some days, especially when the weather was hot, the mood was just wrong, and people were flung around by security guards who had been perfectly civil the day before.

I was only there for a month. But in that time I formed very close friendships with the other protesters, people whose names I can now barely remember; the sort of urgent, trusting friendships which are formed when living in close quarters, with a shared purpose and an outside threat. The days tended to follow a pattern. We would walk along the route, looking for the construction work, and attempt to disrupt it. We would come back to the house and work on the defences, knowing that our eviction would be the focal point of the campaign: boards over the windows and doors, loose chicken-wire around the edge of the roof, secure points we could lock ourselves to. We would cook dinner with food donated by supporters or scavenged from skips, and we would talk about our plans for when the eviction came. And then we would go to bed, lying on bare floorboards in our sleeping bags, crowded together in the first-floor bedroom of the house, listening to each other's breathing and the sounds of traffic along the road, wondering what the next day might bring.

We were prepared for the eviction to take a long time; certainly hours, possibly even days. I was handcuffed to another protester in the loft, our arms joined through a cast-iron drainpipe which had been thrust through the chimney stack. We thought they would have to remove the chimney to get us out. (They didn't. The handcuffs wouldn't fit properly, and the bailiffs just had to pull very, very hard to get us apart.) When the first signs of the eviction had been spotted, early that morning, I'd managed to gather up some food and drink in the few minutes we had before barricading the windows and locking ourselves into place. I'd also smashed a hole in the loft floor through which to go to the toilet – I was pretty nervous, in my defence – and it was through that hole, and a much bigger hole in the floor below, that I was able to watch the outside wall of the house repeatedly bulge inwards and then crumple as it was knocked through with a sledge hammer.

We all had genuine motives for our involvement in the protest. We wanted the road to be stopped and we wanted the nation to move towards environmental sustainability, and we felt that the cause was so vital as to justify direct action. But there was no denying the drama and thrill of what we were doing; days spent running through woodlands, leaping on to moving vehicles, hurdling electric fences to escape security guards. And there was certainly something dramatic about watching the bailiffs clamber into the building through the hole in the wall, with the light pouring in behind them. We listened to them move slowly though the house, breaking through barricades and looking for other protesters. We were still trying to work out exactly where they were when a claw hammer burst up through the floor nearby, and disappeared. Someone started sawing at the joists, the tip of the saw dipping up and down in a cloud of dust. I felt the joists shaking beneath me, and looked down to the sunlit rubble two storeys below, and then half a dozen helmeted and armoured men climbed up through the hole in the floor. It was a very hot day. They were clearly irritated. They looked at me without saying anything.

It didn't seem like so much fun any more.

Jon McGregor's latest book, Even the Dogs (Bloomsbury, £7.99) is out now

To read all the articles in this series, go to theguardian.com/lifeandstyle/series/once-upon-a-life