It is, there are no two ways about it, filthy down here. The oomska has a particularly gelatinous quality that renders it both clingy and apt to facilitate the sudden, oily pivot. Awnings drip with rain. Children walk around swaddled in bin-bags. Tents located in dips, near ditches or, sadly, toilets, have inches of liquid brown squit lapping up their sides.

But let’s not be too downcast about the conditions. First, it has been much worse here. In 2005, after a flash-flood thunderstorm, the backstage area had a current. We played Pooh Sticks by the Kaiser Chiefs’ van. At least this year the ground does not have tides.

And secondly, those over- excitedly yapping “It’s just like ’Nam! I’ve gone totally Colonel Kurtz!” seem oblivious to the fact that they are filming their muddy boots on a Nokia, and are never more than 600 yards from a counsellor, pharmacy, hash-vendor, rock star or bar.

Glastonbury divides into roughly three constituent parts. At the bottom of the valley, where the big stages are, Gap and TopShop-clad punters who “just love going to gigs!” shuttle between the Killers and Babyshambles, ticking off bands on timetables, like Glastonbury is some form of rock I Spy. Up on the hills, the “real” Glastonbury happens: travellers with iron forges; a piano in a shack; people dressed as caterpillars, inching their way through the slime on their bellies.

“That must be . . . visceral,” I offered, by way of chitty-chat. “I have to admit,” Sian, the lead caterpillar replied, “we are going to pupate sooner than originally planned.”

It is up on the hills that the first new Glastonbury pastime of 2007 originates — Mexican cheering. On Wednesday night men dressed as pirates started to cheer — a cheer that was picked up by the next field, and so on across the valley, until 177,000 people were cheering, simply in celebration of being at Glastonbury. A more personal pastime is the dribbling of a football — of necessity a very muddy football — across the fields, as you trudge from Mika to falafel.

The third part of Glastonbury is the surreal part: the backstage VIP area which, in these days of tabloid spreads and Kate Moss’s knees, often seems in danger of subsuming Glastonbury coverage. International paparazzi swarm to get pictures of John Simm, from Life on Mars, dancing to the Coral, Stella McCartney talking to Pixie and Peaches Geldof, or Andrew Marr and Harry Enfield nodding thoughtfully at Paul Weller.

Lily Allen has a pap-avoiding technique: ludicrous disguise. On Friday night she moved about safely concealed in a velvet, and rather fetching, mushroom costume. On Saturday, she was in a felt dragon suit. Glastonbury is, of course, the one place on Earth where a woman walking about in a dragon suit is wholly unremarkable.

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