I took a guest semester at a nearby teacher school during my undergrad. Summers off sounded pretty cool so I considered teaching high school math. My instructors in those courses however completely turned me off. In one exchange with my professor for a Teaching Highschool Math class, she was talking about some boring curriculum that instructed by teaching simple algorithms to solve problems, which student had to memorize and practice over and over, and why it was good we didn't use it in most US schools. I challenged her, asking who uses this type of curriculum? She said Japan, Singapore, Germany were examples of countries that use similar techniques. Then I asked, "But don't all those countries score much better than the US in math and Science?" She finally admitted that was so, and I never got any assignments graded higher than C after that exchange. And then I decided that if people like her decide the curriculum, run the unions and schools, and would be my coworkers, teaching would be a very frustrating profession for me.