Find a seat, unbutton coat, eyes shut, head down, wake me up at London. For hundreds of commuters the daily trek to the office passes in a dream-like state, a chance to claw back your rightful share of winks before work.

But not for Watford-born Andy Leeks. The accounts executive has been commuting for more than a decade, and some months ago balked at the thought of facing another trip surrounded by snoring suits. So the father-of-one did what any modern-day Englishman with a grievence would do – and turned to Facebook to express his annoyance.

“Everyone around me was asleep,“ explains Andy, “the whole carriage. People have literally got out of bed, got on a train and gone back to sleep again. It’s just so lazy!

“I tried to list all the things you could do instead: pay bills, research a recipe, email an old friend – or even do some creative writing.“

Unsurprisingly, his comment drew some fierce responses.

“I must have had about 20 replies saying ’you’re an idiot, everyone sleeps on trains, get over it’. So I made a foolhardy promise to write something on every commute for a year. And just like that, the book was born.“

Three months on, Andy has completed his debut book As They Slept: The Comical Tales of a London Commuter – written solely in the time he spends on the train.

The book, laid out like a diary, is full of observational humour as Andy pokes fun at his fellow passengers, muses on how to eradicate lost property, ponders why women can’t use their pockets, and discovers exactly when it’s okay to lie.

“I’ve got a special seat on the train, which I’ve managed to manipulate since starting the book,“ the 33-year-old explains. “I sit right next to the toilets, by all the bikes. The smell’s awful, but it means I’m not being overlooked by anyone. That’s crucial when you’re writing about other people.

“One day you might be moaning about the fat guy opposite who has just thundered through four cans of Stella, another day the beauty of the countryside. It was about me getting ideas down on a page but it’s kind of turned into a grumpy old man’s notebook.“

Typing on his iPad, Andy writes a chapter each morning, editing the day’s entry on the return journey.

“I look like a guy who is just getting on with his work,“ says the former Langleybury School pupil, “I could be just punching numbers for a big firm. I haven’t got a sign that says I’m Andy and possibly I’m going to write about your bad hair today. I feel like I’m undercover.“

Released as an e-book and in paperback, As They Slept is rocketing up the Amazon charts, recieving reviews that compare the author to the likes of Danny Wallace, Jeremy Clarkson and David Mitchell.

As for the Facebook doubters – Andy asked one to write the foreword: “To my mind this is a pointless book,“ writes Dean Mason “as ill conceived as his lifelong dedication to Watford FC“ before calling the author a “sour-faced cretin desperate to win a petty argument.“

They may take some convincing but Andy believes all commuters could be making more of their journeys.

“I don’t think there’s any limit to what people can do during their commute,“ says Andy, already writing part two of the series. “As long as you can do it on a train and do it legally. I’m writing because that’s what I enjoy. I’d love one day to walk through a carriage and see people juggling, painting, crocheting and knitting. Do something you want to do, anything – there’s no limits.“

As They Slept: The Comical Tales of a London Commuter is available on Amazon for Kindle and in paperback. Part Two will be released in March.