1. About as batshit insane as one can get without being locked in a padded room. One who is headmental acts in an erratic and unpredictable way, so much so that it isn't even funny. They are also observed to say things which blatantly aren't true and often hold grudges over the tiniest things.
2. The state your ex will enter approximately two weeks after impact.
1. Bob: Mutiliate the innocent! I think that I speak for all of us when I say the Phantom Menace was the best Star Wars. I have five nipples.
Jen: Uh-oh, he's gone head mental...
2. I'm sorry, I do love you, just not like that. I love you as a friend, as a brother maybe. I do hope we can still keep some sort of relationship as I'd hate to have hurt you too much.
Pronounced "four-nine-two", this is how a friend of mine describes the "beer goggles effect" that occurs when you end up sleeping with an unattractive girl when drunk. The numbers refer to the marks out of 10 given to a girl based on her looks.
Before you take a drink, the girl in question is marked 4\10 for hotness (i.e. not passable)
When you're drunk and doing the dirty deed, she's a nine.
The next morning, she's a 2, mostly because you can remember what she looked like naked.