know (one's) beans
know (one's) beans
To be knowledgeable about and/or very familiar with something. I had no idea you were such a good piano player—you really know your beans!
See also: bean, know
Farlex Dictionary of Idioms.
- write the book on
- wrote the book on
- wrote the book on (something)
- know like a book, to
- familiar
- familiar with
- familiar with (someone or something)
- know a thing or two
- know a trick or two
- know about (someone or something)