Literally, "You only fight a bear once." Often used as a battle cry of sorts immediately preceding a reckless act in which YOLO is inapplicable and the reward is not likely to feel like a reward at all. For instance, fighting a goddamn bear.
Guy 1: What are you doing at Yosemite this weekend?
Guy 2: I'm going to fight a bear.
Guy 1: You know you'll probably die, right?
Guy 2: YOFABO.
Guy 2: I'm going to fight a bear.
Guy 1: You know you'll probably die, right?
Guy 2: YOFABO.
by Prof. Eugene S. Iverson August 18, 2021