Several studies have documented that students, particularly beginning ones, tend to overestimate how well they're doing in a course. I didn't used to think this was a problem. I thought students who overestimated how well they were doing were talking about the grade they hoped they'd get, not the one they expected to receive. But my thinking has changed. I now believe students are also telling themselves that the grade they want is the one they're going to get, and if they are, they're providing themselves reasons not to spend more time and effort on the course. And because so many students aren't all that motivated to study anyway, a kind of vicious cycle starts in which students think it's okay not to study because they're doing fine in the course.