it takes one to know one
Expressing the same underlying character-judgment themes as pot calling the kettle black or set a thief to catch a thief.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“He called me lazy, but it takes one to know one.”
“When my friend accused me of being stubborn, I laughed and said it takes one to know one.”
“She dismissed his criticism of her dishonesty, retorting that it takes one to know one in such matters of character.”
disputed origin
20th-century retort; descends from the older proverb 'it takes a thief to catch a thief' (17th century).
- 01
as best one can
In the best possible way, given one's circumstances and abilities.
- 02
as far as one knows
To the best of one's knowledge, as far as someone knows or possible information to be gathered about the topic, subject, aspect, or situation.
- 03
as you know
as it is already known.
- 04
back to square one
Located back at the start, as after a dead end or failure.
- 05
be taken ill
To become ill.
- 06
beat as one
To share the same feelings.
- 07
become one flesh
To join together in marriage; to develop a unifying bond as a result of marrying.
- 08
bite off more than one can chew
To try to do too much; to take on or attempt more than one is capable of doing.
Last updated August 10, 2026