Teaching is so much harder than you think it will be

In college courses, professors (who may not have ever been in another kind of classroom) try to tell students that if they have a well-thought-out lesson plan, with all the new learning theories considered, they will have few problems. 

It will take just one year in an ordinary classroom for new teachers to learn that their college courses were mostly useless theory--ideas put together by learned editors/professors/researchers who know very little about working with small people in the real world.

I used to say that when I retired, I'd enroll in a beginning education course.  I think it would be great fun to sit in the back and point out the flaws and fallacies in the course.  Hey, maybe I still will.