Who lit the fire under you? Until you learn to harness and direct your vast mental and physical energy, you're likely to suffer from lots of nervous quirks, like the kid who's always bouncing his leg under the table, or whose fingers can't stay still. You've got plenty of get-up-and-go; your problem is that it just gets up and goes anywhere!
With a little maturity and discipline, though, you can go a long way. Consider your mind and the way you learn -- quickly, in big jumps. You're not very good at sitting down at the table and hitting the books for several hours at a time. You need to be physically active both as an outlet for your nervousness and as a way to direct your thinking. You tend to jump to conclusions, forming opinions without all the facts and then forcefully defending your point of view instead of listening to the input of others. You can be so opinionated that others simply wilt under your certainty. Don't let this happen! Carefully consider what you're passionate about, learn deeply and then express yourself strongly about it. Keep a strict exercise routine so you feel and sleep better. Don't burn your candle at both ends!