I think the differences between people are so interesting. For example, today I'm at work (summer job) I work in a shop that sells alot of fabric, and my two colleagues were drooling over a new tape measure that one of them had bought. I couldn't have told it apart from any other tape measure, but because they measure alot of fabric, they've created their own sort of little subculture. It's so interesting!
And at the same time, they are two completely different people. While flicking through a new fabric book which just came in, L was swooning over the different designs, and at how beautiful some of the material was. Whereas T looked at the pages with a completely different eye. He was working out the profit margins and trying to estimate which would be most popular and therefore generate the most business.
Ohh I just love watching people :)