Do students not realize that teaching is our job? And we get paid??

I had students act surprised that teaching them is my job, and that I get paid to be at school. Their reaction made me think I said something wrong when I mentioned I get paid either way (whether the my waste the class period or not). I’m wondering if I made a faux pas or broke some kind of “fourth wall” by saying that. Do students really not understand that teaching them is a job we are paid to do??