expression
people are blind to their own faults
Proverb meaning it is difficult to recognize one's own shortcomings, just as one cannot smell one's own body odor. Often used to point out hypocrisy or lack of self-awareness.
彼はいつも他人の悪口を言うけど、臭いもの身知らずだよね。
He's always badmouthing others, but he doesn't see his own faults—it's like the proverb says, 'one is blind to one's own smell.'
Similar meaning of not seeing one's own faults while criticizing others, but uses a more vulgar image (eye booger laughing at nose booger).
A traditional Japanese proverb. The literal meaning is 'a smelly thing does not know its own smell,' referring to body odor. The exact origin is uncertain, but it has been used for centuries to illustrate lack of self-awareness.