I kept that pace for 35 years, and when I retired last year, I just wanted to sit down. LOL. Everytime I hear anyone malign teachers the hair goes up on the back of my neck. I turn into a witch, and not just for Halloween (although I am present playing one in our local community Haunted House).
I worked "in the real world" 7 years before I could get a full time art teaching job, and let me tell you, I worked harder as an educator than I ever did as a graphic designer,printing press operator, secretary in personnel or assistant to a collections lawyer. While "real world" jobs have their unique pressures, job to job, you are never "on" for the whole time as you are as an educator. In the real world you can gossip, go to the bathroom, have lunch for 1 hour, curse if you drop something on your foot, roll your eyes at your boss, and pass the buck. In teaching every word has to be measured, your kidneys have to be strong, and you are the boss, so you can't pass the buck. There is no such thing as a bad hair day, a day where you feel horrible, or a day where you want to slow down. The "show" must go on, while you might have taught the color wheel for 30 years, it is the first time for the kids in front of you and you want them to be excited about it. Educators are all too aware that we can, with a look, or a word, harm a student in a way that they won't like our subject matter for the rest of their lives. Believe me when I tell you that the other jobs that I had, none of those bosses or clients remember my name, but there are thousands of my art students that remember mine now.