Dictionary.com
Thesaurus.com

it takes one to know one

Idioms  
  1. The person who expressed criticism has similar faults to the person being criticized. This classic retort to an insult dates from the early 1900s. For example, You say she's a terrible cook? It takes one to know one! For a synonym, see pot calling the kettle black. A near equivalent is the proverbial it takes a thief to catch a thief, meaning “no one is better at finding a wrongdoer than another wrongdoer.” First recorded in 1665, it remains current.


Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

I guess you could say, it takes one to know one.

From Seattle Times • Oct. 4, 2023

Well, first of all, Dean, it takes one to know one.

From Salon • Feb. 28, 2023

Once again, it takes one to know one.

From New York Times • Aug. 25, 2021

"Well, with all due respect sir, it takes one to know one."

From Fox News • Oct. 19, 2020

They say it takes one to know one.

From "The London Eye Mystery" by Siobhan Dowd