Getting so high or drunk that you forget all your troubles and in essence become fucked in two ways.
Someone who is really drunk and will probably lose more brain cells than they can afford
Acting more depressed than you should be feeling; slightly sarcastic.
Jimmy: Get high? Forget about your troubles?
Johnny:...Yeah. Let's get FBR tonight.
Johnny: He's an FBR, he's gonna have a hangover for life.
Jimmy: He's acting so FBR. Like, get over yourself man, you have no right to be depressed.