If you really dont care at all about a person doing/taking something you say "knock yourself out" as in to do/eat until you pass out (if you really want to).
Same as "go for it" or "go nuts".
Person 1: "Hey man, can I have some beer?"
Person 2: "Yeah, Knock yourself out"
to incapacitate or render oneself unconscious by means of physical, or mental, abuse or deprivation to one's own body.
"You are ridiculous. Knock yourself out now!"
"There is no way I can win this race. I might as well knock myself out!"
"I was about to kick that guy's ass for the way he was talking to my girlfriend, but he knocked himself out already."
EBK stands for "Elite Ball Knowledge." 1 In internet slang, "ball knowledge" originally referred to a deep understanding of football/soccer or basketball, but it has evolved into a broader term for having a highly sophisticated, deep, or niche understanding of any specific topic (such as music, movies, or subcultures).
Person A: "That scene was a direct homage to an unreleased 1982 Japanese indie film."
Person B: "Wow, EBK."