I learned that if I run my car at full speed into the back of a parked car, I won't simply crumple into a twisted heap of metal and crush both cars. Instead, I'll ramp over the car in a sideways fashion, and twist the car over itself in mid-air, landing on my wheels at some point down the road. There will likely also be minimal damage to the front fenders, which is nice.
I learned that it's relatively ok to spy on sorority houses and the girls showering inside. At worst, I'll probably fall off my ladder into a bush and smile, or have a finger wagged at me sternly by the house mother. No charges will be laid by police, who will simply play it off as boys being boys.
I learned that you can't ever kill a serial killer, ever. No matter what you do. Especially if they have a prop that makes them easily identifiable and somewhat memorable (i.e. hockey mask, or finger blades). Also, you should never have sex with a hot girl in the vicinity of said serial killer, or you'll be the first to get popped, most likely while you do her.