Don't say you understand when you don't. Size really does matter. A stereo system in your car only impresses your buddies. No matter what you say, your ex-girlfriend is a hoe. If you did something wrong or even if you didn't, apologize.
Fashion police do exist.
We absolutely do not care about monster trucks, car systems, paintball, or anything else you and your friends talk about. Even is you think it is cool to burp, fart, or emit other strange gases from your body, it is not. It is not cool to shoot snot rockets. We will always think we are fat, so humor us and tell us we aren't.