A coworker of mine was a submariner during the Vietnam war. (Old diesel electric re-purposed as a hydrophone platform.) He knew a fellow sailor who liked to get drunk, start giggling like he was a silly schoolkid, look for the toughest guy in the bar, go up to him and slug him. This wasn't just an occasional thing, it was every shore leave. He always got the crap beat out of him, and he was always giggling about it. Maybe it was those endogenous opioids?

It got so his fellow sailors would know it would happen, so two guys always went with him to drag him out of the place when it started. (They had to wait until he already fixated on that other guy, so they wouldn't be his target, which would possibly involve awkward involvement with the military discipline system.)

Sounds like Fight Club.