[mosdef]

there are two possible answers here.

1. you have severe psychological problems, insecurities, etc, and you have an emotional need to ridicule others, bring them down, etc to make yourself feel better about yourself, or to selectively verify your consciously fabricated HIGH opinion of yourself, which is a defense mechanism to mask your subconscious LOW opinion of yourself.

2. you saw a goofball do something goofy and laughed like any normal person would when confronted with something amusing.

i'll go with the the assumption that the simplist answer is the more likely. so, IMO, you can relax and feel okay about yourself. have a beer, buy your girlfriend a present, move on with your life in comfort.