When I was in college it was awful, I could never stay motivated. My biggest problem was that everything came very easy to me (I know, complaining about the wrong thing, right?), which lead me to not being prepared for the really difficult classes I eventually had (since I did not build the correct foundations). In my second BS, though, I am studying a lot of stuff I find interesting and challenging. I think that is key for me, it has to hold my interest, and has to challenge me, or it will not win out against procrastination.