The most challenging aspect of teaching is probably worrying about all of the annoying standards set by the state, and even some national standards (*cough* NCLB *cough*). At the high school level it's not as bad, but teaching to standardized tests while ensuring that students REALLY know what's going on is definitely a struggle for a lot of teachers. In addition, this kind of "equal oppurtunity for all" creates a situation of less focus on the kids who are excelling and have an insane amount of potential. Even with gifted services and advanced courses, I feel that these kids are slightly held back by that wasted month or so every year, where they prepare for OAT's or OAA's or OGT's or Terra Novas or whatever the current name is for these tests. And at the high school level, there may not be as much focus on standardized testing, but teachers still have certain standards for HOW they teach and what materials they can use, or what kinds of methods they must use at certain times. I've had teachers who had teaching pretty much mastered in my opinion, then the class average plummeted for a month as a required "Online" unit started up and less teacher-student communication could occur, or a certain study method was required for a unit that didn't work as well as the rest of the year.