It's 7am. Do you know where your stomach is?

I ask only because I have no idea where mine's vanished off to, and I'd like it back. Last night, this being Edinburgh, alcoholism capital of the world, I went out drinking with a couple of mates; went to a couple of bars, drank a couple of bottles of overpriced Czech import beer, danced a bit, got progressively drunker and started slurring my words, bumping into passing strangers and shouting "yo!".

A typical night perhaps, but then, not four hours later, I woke up, downed an impressive amount of water and got on a train.

If you're reading this from America or a similarly big, spread-out country like Australia, you probably don't realise how integral the train system is to Britain. Just about every little town in the country has a station, even if it's just a concrete platform in the middle of nowhere, and trains actually stop there at least once a day. The car industry has had little chance to destroy the infrastructure, although not through lack of trying, and you can still get wherever you need to go by rail. This is pretty fantastic, even when you factor in the persistent urine smell on Richard Branson's new Virgin Voyagers - like the one I'm on, which stinks like the monkey enclosure at the zoo.

I'm on this particular journey for just short of`seven hours, and I'm not joking when I say my stomach's gone off on a gastrointestinal vacation; or, at least, it's picked up the brochures from the travel agent and is quietly deciding between interrailing around Scandinavia and sitting by the beach on the Costa del Sol. In an effort to quash its impending mutiny through appeasement, I bought a Mexican bean wrap from the newsagent at Edinburgh station; as any European historian will tell you, this was a mistake. The British have an interesting relationship with American food - they don't understand it, and then it gives them indigestion. (Conversely, outsiders have an interesting relationship with British food - they don't understand it, and then it turns out to be blood or stomach lining or celery.) "Mexican", in this case, meant "some beans with about a ton of sour cream and an unexpected lump of spinach in the middle". It's only a matter of time before the spinach, the cream and the beer form some kind of unpleasant lifeform in my gut.

Predictably, just when the nausea gremlin has just started to hock a loogie up my throat, the big, smelly man sits next to me. You heard. You can see me typing, and yet you're going to sit there and pretend to be aloof. (Only the southern English actually do this; I'm taking a chance he's not Glaswegian. The last thing I need this morning is an old-fashioned chibbing because I wrote something abusive on my laptop.) You're so overweight that flubber from your arms is infringing on my seat, and you didn't take the time to shower before you left the house this morning. Neither, I should point out, did I, mostly because I was lying on my bed groaning "nooo" until five minutes before I had to be out the door. But at least I smell of last night's beer and cigarettes; you seem to have rolled in your own vomitous excrement.

Distraction! Sheep! A great big field of sheep! That's one of the joys of travelling by train; the tracks invariably go through picturesque farmland, and there are invariably sheep to take your mind off the man with the whiff machine in his brown trousers. Sheep are nature's President Bush - they wander round with the most amazingly empty expressions on their faces, enjoying the grass and apparently blissfully unaware that they're part of some extremely bloody grand plan. (Which is not, of course, to suggest that Bush enjoys grass. He's more of a cocaine man, ho ho.) It's fun watching the hills and mountains in the distance, touched by clouds and unmistakingly beautiful, set against a flock of gormless sheep with profound dingleberry problems in the foreground, each letting rip with their own personal take on "baa".

There are horses too, but let's face it, they're just My Little Ponies without the cool arses.

Smelly man has gone to get some cheese and onion crisps from the train's wildly extortionate buffet car, so I have room to breathe. Because I'm here with my laptop, I load Winamp up with every Bryan Adams song I own (one, Gone) and set them to repeat. Hopefully he'll see sense and go and sit with the other smelly people, who are sharing an illicit Marlboro Light by the toilets. Mmm, urine and smokes. It's almost as if I've never left Edinburgh.

When I get off in seven hours' time, I'll be in Oxford, which is a different world to say the least; there nobody actually admits to peeing at all, and all the cigarettes are made of peasants. But more on that another time.