know better than

know better

To be aware or capable of better or smarter behavior than one has demonstrated. You know better than to talk to strangers! What were you thinking? You know better than to try to question that professor—he doesn't care what we have to say.
See also: better, know
Farlex Dictionary of Idioms.

know better than

be wise, well-informed, or well-mannered enough to avoid doing something specified.
1989 Anne Fine Goggle-Eyes Inspector McGee knows better than to tangle with Beth's granny.
See also: better, know
Farlex Partner Idioms Dictionary
See also:
  • know better
  • all the better
  • all to the better
  • so much the better
  • better get moving
  • (one had) better get moving
  • ideally
  • be better placed
  • be well, ideally, better, etc. placed for something/to do something
  • couldn't be better
References in classic literature
He must know better than I how great were her powers of self-control.
Moon and Sixpence
Richard, ought to know better than I where the twenty thousand francs went to!"
Richard ought to know better than you where the twenty-thousand francs went to?"
"Why should I know better than you where the twenty-thousand francs went to?
Phantom of the Opera
Of course, I can't explain who it is precisely that I am mortifying in this case by my spite: I am perfectly well aware that I cannot "pay out" the doctors by not consulting them; I know better than anyone that by all this I am only injuring myself and no one else.
Notes from the Underground
Ladies, too, were concerned (I am really afraid I am saying too much) - all sorts of ladies, some old enough to know better than to put their trust in princes, others young and full of illusions.
Mirror of the Sea
He/she argues that our MPs seem to know better than the "people" after the Brexit referendum.
MPs actually do know better in this case; LETTERS
POLITICIANS have been told they "should know better than to share" conspiracy theories about allegations against Alex Salmond.
Nutty Nat theories 'not on'
In an instant you smack yourself in the forehead uttering the epithet, "I know better than that!"
You will keep making the same mistakes over and over
Survivors know better than anyone the steps we need to take to identify those enslaved and bring to justice those responsible.
This is a vital and challenging time for all of us
Indeed, I do know better than your original correspondent because I knew that responding to such verbal aggression would gain nothing.
Dog owner answers back; Mailbag letters also appear online at www.examiner.co.uk/views-and-blogs/reader-letters Mailbag
I've fancied Brian Reid's men from the off but should know better than writing off my old gaffer Michael O'Neill.
City set to test the Ayr
"As for Amanda Staveley, she should know better than to publicly put words in my mouth - particularly words she knows or should know perfectly well aren't true.
Football: Hicks in warning to DIC; EXCLUSIVE
You know better than to think we could get the Stephenses to explain their business deals, and you also know better than to think they would jump out of a long-term investment at the bottom of the market.
Yeah, that's the one
Wright should know better than to use such offensive terminology.
Disability dos and don'ts