I remember a conversation I had with a friend of mine back in freshman year here at Purdue. She was on to her third exam of the week, running on literally no sleep, and she said those exact words. Let's be honest, when we are up late at night studying for that one class that we have to pass in order to get into our major, we are not thinking about how much fun we are having, but rather how it will all pay off in the long run.
So the moral of the story is that even though we may have our days where we don't know why we have to do the things we do, just remember: it will all be worth it in the end.