Someone who takes a conversation or joke way too far. So far that the previous joke is no longer funny and the said "Far-on Reacher just looks like an asshole
Clint: Mitch, do you want an Apple?
Mitch: No, eventually it will be a core!
Clint: HAHAHAHAHA Just like alcohol when you get drunk... you know!!! Funny stuff.(Dumb ass)
Mitch: You are a,Far-on Reacher...