Are you a grade student? Then probably you don't have a girlfriend in your life yet. Once a girl enters your life, the grades will fall below the ground and you will fly above. The journey from being just any other guy to a boyfriend may seem worth it all but your grades may not agree so.
If the girl says yes after the proposal, you may remain just as average other guy who has a girlfriend. And the guys get depressed after a rejection eventually may realize the truth and may go above the point from where they actually started.