I've been asked to clarify so here goes. Firstly I think a few posters are bundling a couple of passions/preferences together. I said it doesn't make sense to be passionate about teaching Pre-U, because I think this would be more a case of preferring to teach a certain age group, or maybe a perceived status in teaching a subject at a certain level. I never said that teaching Pre-U implies a passion for one's subject. I was arguing from the other direction, which is not equivalent. Now, I also conceded that someone who didn't teach Pre-U could still be passionate about their subject, as one's level of ability doesn't necessarily equate to one's passion. However I would still maintain that some one who is passionate about something usually wants to take it to the limit. I love playing tennis. I'm not especially good at it, but I want to play opponents who I find very hard or impossible to beat. Likewise, I enjoy skiing, but I don't want to just cruise the green or blue runs, I want to get my teeth into the odd black. As for people who are good at their subject but don't want to teach it at Pre-U. Maybe they are passionate about it, but I would then argue that they are maybe more passionate about teaching other age groups. As I said earlier, I also enjoy teaching younger students. However, Pre-U sometimes throws up problems I have to think a bit about, and explaining stuff to students can be more challenging. This is what I enjoy - not, as MM suggests, Pre-U per se. In fact, as the maths journals will testify, I also like to tackle challenging problems outside the classroom. This is why I would insist on having Pre-U classes (though certainly not exclusively) I teach because I enjoy it, and I want to maximize that enjoyment.