My feature film debut is all because of a book I wrote a couple of years ago, called Yes Man. It's the story of how I'd been saying No far too much in life. I'd been staying in, and lying low, and batting away the various invitations that were coming my way. I was hiding out, and claiming I couldn't come over or see that friend or attend that gig because I was ... you know ... doing a 'thing'. And then everything changed. Because I said Yes.

And now, suddenly, here I was, standing opposite where Jim Carrey had been just before being whisked away, on a Warner Bros, studio lot, with my own huge trailer and an executive by my side. Because Yes Man is being made into a film.

'If you're not busy tonight,' says the exec, 'a colleague of mine would like to take you out to dinner ... He knows your work very well and would love to ask you about it ...'

'Of course!' I say, flattered. 'It would be a pleasure?

It is good being flattered. So long as you don't believe it too much.

The stand-up, Adam Bloom, once told me of his excitement at attending the Montreal Comedy Festival. He had been spotted. By an exeeutive. This was it!

'You were PHENOMENAL!' she bellowed. 'Please! Come to this party tonight! Casey will give you the details ... Casey ... this is Adam ... he was PHENOMENAL!'

Adam turned up at the party, all spick and span, and was pleased when the exec approached him once more. 'You were PHENOMENAL!' she said. A moment later, he overheard her pointing him out to a man with an important face. 'That guy,' she whispered, 'is phenomenal!' Adam nearly imploded with joy. Until she returned, five minutes later, with a small plate of crisps in her hand. 'Ohmygod, you have got to try these,' she said. 'They. Are. PHENOMENAL?

I think Adam left soon after, when he realised they were just Pringles and, as such, not particularly phenomenal.

But that won't happen to me tonight, I think. After all, I've just been filmed under a dead moose.

I arrive at the Chateau Marmont. Terence Stamp has just wandered upstairs. Dawn from The Office is talking to a goggle-eyed Australian. Someone who looks like Ryan Seacrest has just spilt mineral water down his trousers. And the new executive has popped open a bottle of champagne.

'So I have to say,' he says. 'Big fan. Big fan.'

Clearly, he thinks I'm more important than I am. Little does he know I was recently bumped from Celebrity Win, Lose or Draw in favour of a bloke who hadn't been in EastEnders for twenty years.

'There's so much to talk about,' he says. 'But mainly, I want to know what it was like ... running the marathon?

I smile. And I don't know what to say. Because I have never run the marathon.