what has been seen cannot be unseen

what has been seen cannot be unseen

Disturbing or upsetting images are not easily forgotten. Even though I'm back from the battlefield now, what has been seen cannot be unseen.
See also: been, cannot, seen, unseen, what
Farlex Dictionary of Idioms.
See also:
  • I'm afraid
  • I'm afraid...
  • off the radar
  • on/off the radar
  • I'm sorry to say
  • suck the big one
  • suck a big one
  • suck donkey balls
  • a sad state (of affairs)