Straight edge is everything about a personal decision to not live my life under the influence or not being aware. I pretty much don't like anything that alters my view of reality or my perception or my grasp.
Everybody knows how to throw a punch. Not correctly - he or she might not know how to turn the wrist or know what part of the hand to hit with. But humans instinctively know to fight, whether they bite or claw or pull hair. It's an instinct.