I agree with posts #1 and #2. I really didn’t figure out until graduate school just how powerful it is to be ahead in your homework, rather than just caught up. This means that you are better prepared when you walk into each class, which means that you pick up a bit more in every class. This in turn makes it easier to keep ahead.
A lot of students don’t take any economics at all in high school, but then take it in university. I quite liked economics when I finally took it in university (macroeconomics as an undergrad, and econometrics as a graduate student).