身み知しらず

na-adjective, noun

self-conceit; overconfidence; neglecting one's health

Describes a person who is overly confident or reckless, often ignoring their own limitations or well-being. The 'neglecting one's health' nuance is less common and typically appears in contexts of pushing oneself too hard.

• 彼かれは身み知しらずにも、一人ひとりでその大おお仕し事ごとを引ひき受うけた。

  He was so overconfident that he took on that huge task all by himself.

• 身み知しらずの行こう動どうで、結けっ局きょく体からだを壊こわしてしまった。

  Through reckless behavior, he ended up ruining his health.