He developed an all-or-nothing mentality after the competition.
Он развил всё или ничего менталитет после соревнования.
Definitionen
An all-or-nothing mentality is a cognitive pattern where individuals view situations in black-and-white terms, believing that things are either completely successful or a total failure, with no middle ground or shades of gray. This mindset can lead to extreme behaviors and unrealistic expectations.