The first Iain Banks book I read was The Wasp Factory. I knew I was going to enjoy it, so I put it aside as a reward for finishing my finals at University. It sat on my shelf, a deferred pleasure.

I remember the circumstances of reading it vividly – I had been to our graduation ball and, unable to sleep after a very drunken, flirty evening, I collapsed on my bed and picked up the book. I didn’t sleep that night at all. I devoured that story and, still awake at 6am, I went for a walk in the early morning mists, my head swimming with excitement about my future, and the strange, dislocated sense of formless dread that Banks had conjured in me.

“Come outside,” the book seemed to say, “the world is far, far weirder than you could possibly imagine…”

Looking back on that moment of transition, it feels almost as if it was Banks himself who ushered me out of adolescence into the wider world with a warm but slightly ghoulish grin of amused invitation.

I read The Crow Road in one sitting, too, in an attic bedsit in Brussels where I hid from the menagerie of freaks who shared the house with me – the mad, snaggle-toothed landlady, her grotesquely fat son who read books about nineteenth century post codes, the alcoholic Aussie tennis coach, and the Irish girl across the hall, who I loved with a fervent, unrequited passion – they swim in and out of Gallanach in my muddled memories, no more real than Uncle Rory, Prentice, Ashley and the rest.

Two years later Whit kept me company as I languished at home with flu, feverish and delirious, bedridden for a month, living on soup and stories. I recall little of what happens in the book – I just retain an impression of vivid, formless colour and a girl brandishing a water pistol filled with tobasco, laughing wildly.

Complicity held my hand and whispered dark revenge fantasies into my ear as I hid in another attic, this time of a private school in the middle of nowhere, surrounded by children of all ages, playing at being adult much as Cameron does.

I picked up The Business immediately after hanging up the phone to reject a very generous job offer from a large company who really wanted me to work for them. I had initially accepted the job, but upon being presented with the contract, I noticed they had a dress code and, instinctively rebelling, I retracted my acceptance to the utter, outraged astonishment of the recruitment agent. Torn between exhilaration at my defiance and fear that I had made a terrible mistake, I sought solace in Banks’s corporate fantasy, and was immediately reassured that I had done the right thing.

I can’t recall where and when I read the other books, but I devoured them all, many more than once. The shock of Use of Weapons‘ double twist was so profound that I remember exactly how it made me feel, but all attendant detail was washed away by the brilliance of the denouement – that memory sits in splendid isolation.

But the one Iain Banks book I have never read is The Bridge.

Banks says it’s his best. I take his word for it so, much as I saved The Wasp Factory for the last day of my adolescence, I’ve been saving The Bridge for the last day of my adult life -the plan has always been to keep it safe for the day I am diagnosed terminal.

Seriously, that’s always been at the back of my mind. Accidents notwithstanding, we all get that bad news sooner or later, and I have The Bridge set aside for that day, sitting on my shelf, a deferred pleasure.

In his heartbreaking, dignified, funny statement yesterday, Banks said he and his wife will be spending his final months ‘seeing friends… that have meant a lot to us’. I’ve always though that I would want to do the same when the time comes, and he is one of the friends I plan to spend that time with, reading the book he considers his best. That way, as I face another transition, Banksy will be there, grinning wolfishly, ushering me through another door – a companion, a guide, a mentor I’ve never met, but who’s been one of the best and wisest friends a man could wish for.

I will miss him terribly, but I know he’ll be there for me at the end, in the pages of a book, as he has been so many times before. And for that I am more grateful to him than I can adequately express.