Challenging the referee in a boxing match and getting your ass handed to you
/r/instant_regret: "What have I done..." - Instant Regret (in'-stint rē-gret') n. a subreddit dedicated to deliberate actions that unexpectedly lead to undesirable consequences and horrible results; things which may cause someone to say, "oh man, did I just screw the pooch!" - February 3, 2022 - 21:33