By Duke of York Square I sat down and wept

The other splendid thing I did in London happened completely by accident. By the end of my trek up the Kings Road I was getting thoroughly hacked off. My toothache had intensified to the extent where I couldn't think of much else and my iPod was behaving as if it was running to a secret playlist called "songs Nathan's really not in the mood for at the moment". And then I stumbled upon a food market in Duke of York Square at the top of Kings Road. Two months ago this would have been an inordinately exciting event for me. The market was full of stalls selling many of my very favourite things - one stall for handmade chocolates, another selling duck confit and tins of foie gras. At least two stalls were selling cheese of every conceivable variety. Then there was the stall selling Pie Minister pies - beautiful short crust pastry stuffed with tasty chicken or steak. That's before we get on to the spicy Jamaican chicken patties. This was a major setback for me after weeks of doing the right thing.

It was a bit like getting to the gates of heaven and finding they're locked. And having to look through the gates to see loads of people you really don't like on the other side having a great time. Look, there's Natasha Kaplinsky enjoying a canape! And Chris Moyles with a big fuck off Martini that should have been yours! Vernon Kay then strolls by smoking a cigar - the fumes faintly waft through the gate making you feel like an especially pathetic parody of the Bisto Kid. Surely things can't get any worse? Then you realise you're not alone on this side of the Pearly Gates. Enya and Mika have just arrived and they're about to perform "Especially For You" as a duet FOR ALL ETERNITY.

Where was I? Oh yes, so as you can see, I had a bit of a wobble. Suddenly I felt very tired, very hungry and very alone. And did I mention that I had toothache?

And that's when Charles Saatchi stepped in to rescue my afternoon. Now, I've always hated the Saatchis and I've always hated the Tories and when Saatchi married Nigella Lawson I found myself thinking Why don't Al Qaeda do weddings? It's just not fair. But to give credit where it's due the Saatchi Gallery, just off Duke of York Square, really was quite interesting. They had an exhibition of new art from the Middle East which isn't normally the sort of thing I'd go for. But I was feeling a bit down and I thought it couldn't possibly be any worse than watching countless people wandering past munching on a spicy Jamaican chicken patty. So in I went.

I'm no expert on art or culture and I wouldn't even say I necessarily know what I like. I do enjoy modern art because even when it's bad you at least feel like it's bad in an interesting way. Many's the time that I've walked out of Modern Art Oxford with Kelly saying "What in God's name was that all about?", but at least it prompts a conversation. Give me half an hour with the worst stuff in the Pompidou Centre over half an hour with the best stuff in the Louvre any day. And I still really don't understand people who can look at a painting for hours on end. I saw "Guernica" in Madrid and there were people sat on the bench taking it all in for the best part of half an hour. I'm surprised some of them didn't bring a picnic and a blanket.

I think I've just given you a very clear idea how much of a Philistine I am. So back to the Saatchi Gallery. Here are the three bits of art I especially enjoyed. First of all, Spectre (the Yacoubian Building, Beirut) by Marwan Rechmaoui. It is, I later discovered, an exact replica of the artist's former apartment building which was evacuated during the conflict with Israel in 2006. It was an impressively grim and depressing edifice - but if somebody had told me right there and then that this piece was called A Lifetime of Flora and Brown Bread I would have believed them.

The second piece was even weirder. Titled Old People's Home by Sun Yuan and Peng Yu it consisted of a number of frighteningly realistic old people who scoot randomly round an empty space in motorised wheelchairs. You can either look at the whole spectacle from the viewing balcony or go down the steps and walk among them. I did the latter and it was a very unsettling experience. Now I don't know who has an idea like this and I probably wouldn't want to be them. Nor would I necessarily say I enjoyed it. But I thought it was interesting and to me, that's probably enough. Back up on the balcony I got my film camera out and was taking a few shots. An older lady standing next to me said "Take one of the Greek one, it's really funny." So I did.

The last piece I really liked was The Bed by Will Ryman. This is a giant papier mache sculpture of a man in bed, surrounded by detritus - an open packet of Doritos, a watch, a key ring, dog ends, a notebook and empty beer cans. I wasn't sure what to make of it - I suppose I associated with it because it reminded me of living alone in Oxford in conditions best described as squalid. It was also faintly grotesque but at the same time I was amazed by the little details - papier mache tortilla chips, the way the dog ends looked bent in exactly the way cigarettes do when you put them out. Creepy yet compelling.

It probably says a lot about how low I was feeling that an abandoned apartment block, a wheelspin of aged paraplegics (this is a new collective noun I have just coined) and a giant papier mache chainsmoking drunk managed to cheer me up, but that's art for you. I left the Saatchi Gallery with my glass maybe two fifths empty instead feeling more like finishing my trek through London. So thanks, Mr Saatchi. Even if you are a hideously rich Tory bigot and your wife makes me want to throw bricks at the television.