I am obsessed with Fortnum & Mason, and the jams of the England that never was but could be. It is, of course, a class-based obsession for the lower-middle to the upper-middle classes (but not below or above): a very pantomime of Englishness. It is, essentially, imperialism made gaudy with jam. Where do you think all those hampers were going in 1880? Kent?

So Fortnum & Mason is rather more than a department store with a pleasing clock and a faint air, even now, of Grace Brothers. It serves also to make rootless cosmopolitans — I mean Jews obviously — feel safe, even if we are supplanting, by demonic and any other means to hand, everything that is noble in the fake socialist dystopia that is the Labour party. That, amazingly, considering where the jam was going (it really wasn’t going to Kent), you are in a benevolent world that welcomes you, in your strangeness, your industry and your indefatigable longing for jam. No one will throw you in the sea. OK, they did in 1290 but that was only one time.

I have never met a branch of Fortnum & Mason I did not like. I go to the Diamond Jubilee Tea Salon on Piccadilly for tea and the cake carriage — I love the idle grandiosity of ‘carriage’ — and I go at Christmas to watch a German Christmas become, through magic and will, an English Christmas. I buy strawberry jam on the ground floor for £5 a pot. I go to the satellite branch at St Pancras station and now I am in the branch inside Heathrow Terminal 5 at 5.30 a.m. My commitment to this myth is absolute.

Fortnum & Mason is always weird, but this is the weirdest Fortnum & Mason I have found. There is a shop, in which the jams are arranged like religious imagery — the raspberry is the Virgin, I think, and the lemon curd the child — and a bar on the concourse with its mottled grey floor, in the spindly art deco style with pale green leather.

It is easy to forget you are in Hounslow; and you are not just in Hounslow. You are in a theatre in an airport terminal in Hounslow. This is the posh side of the terminal; too near Boots and the cognitive dissonance would overwhelm. Instead, it’s near Burberry and Louis Vuitton, should you need a long-sleeved bicolour belted dress for £1,880 or a medium rucksack in technical nylon and leather for £990. I think airports tell us what is important in the late capitalist age; what we would grab as we mount the last plane before the flood. The answer seems to be blended whisky and nude lipstick, and why not? Both are potentially mind-altering.

It is barely past dawn but Fortnum & Mason will sell you an alternate reality at almost any hour. We are handed vast menus: breakfast; sea-food; alcohol; teas.

We eat a toasted bacon sandwich, which is fine; tomatoes on toast, but the tomatoes should not be here, being green and hard; and plates of smoked salmon, which are perfect.

The empire is gone but still they favour maps. A map shows which expeditions Fortnum & Mason have provided provisions for. It says that in 1928 they sent foods for a civilian Zeppelin to the Arctic; and in 1914 to Shackleton’s Imperial Trans-Antarctic expedition (it hints that this is why they survived, and I am ready to believe it); and the first British expedition to Everest in 1922, although even the strawberry jam couldn’t push them up on that occasion.

I like it, for it is a wonderful metaphor for the separateness, and the obliviousness, of wealth. It’s a lie, of course, but it tastes good.