To Go "full mental jacket". A play on the phrase to go "full metal jacket", made more popular in conversation following the Stanley Kubrick film. To go into a mental irrational verbal tyrade or rant completely unprovoked and exaggerated to the point of WTF.
To lose one's mind verbally on another person unprovoked, going into a complete insane rant making little sense at all, either in text online, comments, blogs, flaming, or in person.
Janie: I am so hungry, I couldn't wait for class to end.
Zena: Assholes like you make me wish breeders would stop having children. You pussy, skank, ho, bitch....
Janie: wtf is wrong with you? I just said I was hungry and you went full mental jacket on me, You need help, srsly.
1) Movie made by director Stanley Kubrick. Intense 'Nam movie that almost seems like two movies, as it is split between Marine Corps. boot camp and the war itself.
2) A type of Ammo. FMJ is usually fully enclosed in metal. Kinda hurts.
The single best piece of entertainment ever fucking created, Full Metal Jacket is the Jesus of badassness. It includes such badass stuff as the U.S. Marines, ten minutes of the best chewing out known to the civilized world, machine guns, Ak-47s, M-16, hookers, R. Lee Ermey,and lots of stuff blowing up, all in one movie.
"where you fromprivate?"
"sir, texas sir"
"Texas?, Only steers and queers come from texas, and you dont look like no steer:
"how tall are you private?"
"sir 6'1'' sir"
"I didn't know thy stacked shit that high"