This is a real shocker, right? Of course teachers take joy in torturing students with mountains of homework and giving detention. They would never want to do anything else. They don't even exist outside of classrooms.
What, you didn't know that? We evaporate if we try to go anywhere the normal public goes outside school hours. Very painful.
Seriously, there are times I think to myself, "I should be more strict and stern. I'm supposed to be the adult in the room." But my students make me laugh too much. (Not all the time, but in some classes, often.) Then I remember that super-strict isn't my style, and in those classes with lots of laughter, the kids are still learning. Laughing while they do it means they often hate math without hating math class. Sometimes that leads to not hating math so much, either. I'll take what I can get.
Here's something students don't always believe: Just like they have days when they'd rather not have to think so hard and work, there are days we'd rather not think so hard and teach. But because we're grown-ups, we suck it up and do it anyway. It's always nice to see teenagers reach that point of realization. "I don't feel good/I'm tired/I'm distracted, but it doesn't matter. I have to get the job done anyway."
There are other times when the knowledge that I'm the adult in the room is a little scary. When a student is upset, or gets hurt, or two of them are spiraling toward a full-out brawl ... I have a split second of "Yikes! I'm the one who has to handle this."
And then I do.
So remember, teachers are people, too. If you're a parent, make sure your children are aware of that little-known fact. And if you're a writer, try not to make every teacher in your writing a one-dimensional caricature. ;)