Thing is, I did understand it. Hell, I looked through my notes from maths degree (5 years ago) and guess what - most of it seems like nonsense. The worst bit is that because these were notes to myself - jam packed with comments of "so obviously" followed by a transformation I can make no sense of at all.

It makes me pretty sad to think what a waste of time that learning was. Also the flip side of "hehe - I was well smart" is "shit - I'm now a moron"