I went to the topology courses. You know, people – Hilton and Wylie gave courses on algebraic topology – and so I did quite a bit of that, which was helpful background to the sort of differential geometry – global differential geometry – that Hodge did. Characteristic classes were just in the air and so it wasn't a single subject, there was a bit of back up on the topology side. But I didn't know much differential geometry. I'd been to a course he gave on Riemannian geometry, I suppose. But it was… and once you start you do research, of course there are all sorts of difficulties you know, everybody has. It was certainly different from what you… it was a quantum jump from what you did as an undergraduate, the kind of geometry there to what he was doing. He was going a bit into, sort of, unknown waters. The topology gave one a bit of a clue, but otherwise it was a bit of a gamble, yes.