Controlling your impulses gets easier with age and experience. At your age, I think I'd ask myself about the long-term consequences of any decision I made before I acted on it.

It's hard to think long-term when you're young...at least it was for me. I wouldn't think of the consequences of anything I did. That's not to say you should obsess over consequences, but it pays to remember that the future will come, even if you mortgage it...man, I wish someone had given me this advice back when I was your age, thinking back on things.