People don't believe me when I tell them how I get my inspiration

Readers are convinced that the only story to tell is the story of your life. Until you stumble upon Noe-Beaver

Omitted mention, in last week's panegyric to San Francisco, of a lovely little park, the size of an apron, situated in the gay suburb of Castro at the junction of Noe and Beaver Streets. You heard me - Noe and Beaver Streets! What chance of finding, in the heart of this predominantly male homosexual Shangri-La a well-tended, spiky-shrubbed community garden (with locked gates) called Noe-Beaver? - beaver being, as I don't have to remind my raffish readers, American slang for the female pudenda. Odd, in that case, that the gay women of Castro haven't sought to change the name of the junction. To Yess-Beaver, say, or Moore-Beaver. Or Noe-Schlong.

Omitted mention, in last week's panegyric to San Francisco, of a lovely little park, the size of an apron, situated in the gay suburb of Castro at the junction of Noe and Beaver Streets. You heard me - Noe and Beaver Streets! What chance of finding, in the heart of this predominantly male homosexual Shangri-La a well-tended, spiky-shrubbed community garden (with locked gates) called Noe-Beaver? - beaver being, as I don't have to remind my raffish readers, American slang for the female pudenda. Odd, in that case, that the gay women of Castro haven't sought to change the name of the junction. To Yess-Beaver, say, or Moore-Beaver. Or Noe-Schlong.

Could be, I suppose, that they are all too grown up in San Francisco to care or notice. But while I am standing there, one foot in Noe and the other in Beaver, marvelling at the happy conjunction, I overhear a gay man, who happens to be wheeling a small child in a pushchair (children in pushchairs being must-have items if you're gay in San Francisco), discussing quinoa on his mobile phone. I am able to deduce - don't ask me how - that he is talking to another gay man who also has a child, and neither is sure how many quinoa cookies make an adequate breakfast for a two-year-old. "So where are you speaking from?" the father on the other end of the line must have asked, because the reply comes back "Noe-Beaver", followed by a laugh.

So it isn't just me.

People think you make these things up. Tell them it's novelist's serendipity and they look at you suspiciously. Which is inconsistent of them considering how biographical everyone is in their reading today, convinced that the only story you have to tell is the story of your life. Until, that is, you stumble upon Noe-Beaver. Then they think you're fabricating.

Coincidentally - except that there is no such thing as coincidence if you're a novelist - I was interrogated on just such writerly matters at Heathrow airport en route to San Francisco. One of those random security spot-checks. Not the sort that goes: "Has any terrorist packed your case for you? Are you carrying a Samurai sword? What about nail scissors? Enjoy your flight." No, this was the business.

Cases on the table, security guards with surgical gloves sliding their fingers under the collars of your shirts, even your cuff-link box examined for secret compartments. I approve of exhaustive baggage searches. Better if they're happening to someone else, but as a person of vaguely Middle-Eastern appearance I submit to them philosophically when stopped, because if they let "me" past without a second glance who else might be slipping through?

As far as I could tell, though you can never be entirely sure, the writerly interrogation had nothing to do with airport security. It was more about the Sikh security man's ambitions to write a novel himself one day. How he knew I was a novelist I can't imagine, unless that's just something you can tell from a person's wardrobe. Novelist's shoes - maybe I'd packed a few too many pairs of those. What he wanted to know, anyway, was how you start. "Where do you get the words from?" he asked me.

A tough one, that. "You immerse yourself in words," was the best I could manage in the circumstances, "and at last they come to you. Words are your medium. If you don't have those, you might as well forget it."

Not true, of course. There are countless successful novelists who have no words. But I took the liberty of assuming he wanted to be a good novelist.

And I was right, because his next question was one only a good novelist in embryo could have asked. "But you must employ so many words," he said. "Don't you worry you might one day use them up?"

He was a charming man with impeccable manners and teeth worth about a million dollars apiece where I was going. If you sell your teeth, I wanted to tell him, you'll make far more than you will writing novels which evince concern for words. But I could see that the other security staff were losing patience. They hadn't stopped me so that their literary colleague could start a conversation about the exhaustibility of language. There were things of more suitcase-associated importance they needed to discuss, such as the number of ties I'd packed for a three-day trip to San Francisco. Almost as hard to explain the ties as where words come from. I just happen to be a word and tie person. Even though it's unlikely I'll wear one (a tie, I mean) where I'm going, I like to travel with a variety, one for each shirt - and I travel with a multiplicity of shirts (hence the boxes of collar stiffeners) - just in case.

A nutter? Maybe. But they can't stop you from flying for being a nutter. So it was thank you and have a good flight, or it would have been had the indefatigable Sikh not found a final question for me. "And the stories? Where do they come from? Do you sit at your desk for years on end and make them up?"

"No," I told him, "I catch planes."

Funny, but they never believe you. Walk the cliffs from Eastbourne to Beachy Head and you'll find a proliferation of wooden memorial benches, all facing out to sea, all bearing melancholy inscriptions, all heartbreaking if you're the memorial bench fanatic that the hero of my latest novel is. Some reviewers have doubted their existence. Too unlikely. Too convenient. Too much of a coincidence that he should find them while out walking, looking for sorrow. But the truth is that's exactly when I found them, while out walking, looking for sorrow. God is good to novelists. He puts things where they hope to find them. Such as Sikhs with literary ambitions at Heathrow. Or a place called Noe-Beaver, plumb in the middle of homoerotic San Francisco.