Those of you who have had the misfortune to be in a bar with me (and really, who hasn't?) know that I laugh easily. I laugh because: A. I'm usually drunk. B. I'm deranged. C. You are a funny person. Often, it is all of the above. But what makes a person funny? What is it that makes one person twist a thought just so, and say the line so right, that it surprises us and makes our diaphragm con…