My interest in any particular piece of mathematical content varies. There are some things that I think are just absolutely fascinating, others…nah. So I think if I was, at bottom, motivated by a love of mathematics then my teaching would ultimately suffer for it.
Working with children, the future looms: I want these kids to have skills, to pass the tests, to get into schools, to get through college, to find meaningful work, to be able to see the world differently in the (hopefully) long, long time they’ll spend outside of schools. But when you take a look at what is genuinely preparatory out of what we’re supposed to teach, it’s hardly everything. People say that school math is mostly useless, and I do see what they mean.
So the answer for me is in the present, and I don’t worry too much about everything else that’s going on. The situation is that four or five times a day, a bunch of people get into a room and are supposed to study mathematics. I honestly don’t know why they’re supposed to study mathematics, but that’s just it: they are.
They are in this room, and I am also in this room and am supposed to help them learn it. If I quit tomorrow, someone else would do it, but I haven’t quit and I am in the room.
So given all this, the question for me is always, how can I do my job without making anybody feel dumb or miserable? And that gets me pretty far.