The Gherkin won't be finished inside for some months, but its raw innards are compelling. I have clambered about inside it, stared down through its spiralling triangular lightwells, stood under the glazed dome at its tip, wandered around the ambulatory at its base, and insisted on going to the private floor where a sky-garage of mechanical equipment is marshalled, designed to pop out of the side of the building and clean it in sundry ingenious ways. I have seen how its main, diamond-lattice external structure neatly segues into the more delicate, wider-angle geometry of the top section. Oh yes, I've got quite intimate with the Gherkin. And every day, like millions of Londoners, I see it from the top of my street. Everyone is aware of it. Nearly everybody likes it. It's a genuinely popular thing. Why is this?

For Foster, this is the building that restores his reputation in the capital after the wobbly physics of his Millennium Bridge (now fixed) and the wobbly aesthetics of his City Hall for the Greater London Authority by Tower Bridge, which sadly can never be fixed except by demolition. The Gherkin, in contrast, gets most things right. In fact, it gets so much right that I feel a bit of a heel for noticing things about it that remind me of - what? Can this be? Richard Seifert?