More food for thought about what we can realistically expect to accomplish in the classroom, from The Teaching Professor:
...every student there experienced that same day in different ways and all those ways were different from what we experienced.It's just not likely that we will reach every student, every day, in the same way; the best we can hope for is to maximize the number of students that we do reach. The big point here - one that I have a particularly hard time keeping in mind - is that much of each student's experience has absolutely nothing to do with what we as teachers are trying to do in the classroom. I know that for me, I spend so much time working on my classes and thinking about how to create an environment in which my students can learn, that by the time I walk into class, it's hard to remember that my students have probably spent very little time since the last class meeting thinking about economics and they likely have a million other things on their minds.
If you think about this too much, it can drive you crazy. So much of it is so out of our control. Teachers can control how well they prepare and that does help to ensure that things go well in class for more as opposed to fewer students. But teachers can’t control what students bring with them to any day in class—what’s happening in their personal lives, how well prepared they might be, what background experiences influence their reaction to this material, how ready they are to learn, whether they come to class with a headache or have an exam next period…
There’s not much point worrying about what’s beyond our ability to control.... We might want to start saying, “Class went well for me today” and stop saying, “The students really learned a lot from that activity.”