I've enjoyed teaching, but I'm glad to be back down to just a full-time job (the day job that provides health insurance). As inevitably happens, the handing out of grades isn't beautiful--with a fairly normal distribution of grades.
I tell students at the start of every semester that I don't believe in grading on a curve. If everyone studies hard and learns the required material, I would be overjoyed to hand out nothing but As. But it never works out that way. Some students simply don't have the memory. Some aren't interested in enough, perhaps because they are too busy with other classes or responsibilities at work or with family. Some get sick--one student was out for two weeks with surgery, although he made a game effort at keeping up, and passed the class. Another was knocked out in a lacrosse game, and out most of a week (but still got an A).