There used to be a saying among fans that the golden age of science fiction was 12, but that was before sci-fi took over the world. Bob Fischer reckons he was a “fully fledged geek” by the age of 5, after first seeing Star Wars.

For him, the golden age was 1981, when he was 8 and obsessed with all things science-fictional, like the rest of his primary school. Even the supply teacher wanted to discuss the latest episode of Doctor Who: “It was that kind of era.” He began composing an epic adventure story featuring himself and his best friend Richard fighting robots, birdmen, snakemen and assorted evil aliens in outer space. “This one's going to be published,” he tells his mum. And he was right. Eventually.

Aged 32, with the usual baggage - job, mortgage, long-term girlfriend - the grown-up Fischer found himself wistfully recalling how his favourite TV shows had allowed him to escape from ordinary life, and decided, on a whim, to attend a Doctor Who convention in Stockton-on-Tees. He then signed up for others dedicated to Blake's 7, Robin of Sherwood, Red Dwarf, The Prisoner, and Terry Pratchett's Discworld, even though it meant spending all the holiday money. Why did he do it? “I'm a broken man, and the eight-year-old boy who sat down one breezy Saturday afternoon to write The Battle to Save Earth has reasserted control over my psyche. And this time, no power in the Universe can stop him.” The book that resulted amusingly chronicles one man's relationship with fantasy, with tales from his youth (constructing a replica of K-9, memorising Monty Python routines, playing Dungeons and Dragons) interwoven with his present-day experiences (drinking himself insensible, star-struck in the presence of the Sixth Doctor), and includes his youthful attempt at a novel, complete with rather fetching illustrations.

Conventions rarely offer much in the way of high drama, and aren't really as strange as the occasional weird costume may suggest to an outsider. There's a lot of talking and drinking, not to mention queueing for autographs, but I've heard that librarians' conferences are much wilder. To add variety to his quest, the author also participated in a water-pistol fight in a disused Dorset quarry (organised by fans of The Hitch Hiker's Guide to the Galaxy), dressed as a medieval monk for Monty Python Day at Doune Castle, and wandered through a Star Trek-themed maize maze in York.

I had hoped for some penetrating insights into fandom, and feared the cheap and easy put-down of my own kind, but Fischer's approach is entirely personal and engaging. He writes with a great deal of affectionate humour - most of his jokes are against himself - and anyone who agrees that “Star Wars was a defining moment of our collective childhoods” will love this book.

Wiffle Lever to Full! Daleks, Death Stars and Dreamy-eyed Nostalgia at the Strangest Sci-Fi Conventions by Bob Fischer
Hodder & Stoughton £12.99; 325 pp Buy the book here

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