From Alexander Maksik’s novel You Deserve Nothing:

p. 87
You always begin the same way. You’re standing on stage, presenting yourself, happy to be back. Which is not to say that you don’t believe in teaching, because you do. There are few things you believe in more and you want to do something good. But along with that comes the wonder of standing before a group of people who love you, who imagine that you are strong and wise.

All that attention, it’s hard to resist. And if you’re honest you acknowledge that before you ever became a teacher you imagined your students’ reverence, your ability to seduce, the stories you’d tell, the wisdom you’d impart. You know that teaching is the combination of theater and love, ego and belief. You know that the subject you teach isn’t nearly as important as how you use it.

p. 169
That’s why the ones who stay are some of the most depressing people you’ve ever met in your life. It has nothing to do with their age. They’ve stayed because of their disposition — bitter, bored, lacking in ambition, lonely, and mildly insane. With few exceptions, these are the people who are capable of staying in a school. This is what it takes to teach for half a life-time. The ones who care, who love the subjects, who love their students, who love, above all, teaching — they rarely hang around.