be a law unto yourself
be a law unto (oneself)
To do whatever one desires and/or ignore rules and regulations. If you need to delegate, I wouldn't ask Gina—she is a law unto herself, and it's hard to persuade her to do anything she's not interested in. How many times has Jason been arrested now? Geez, he sure is a law unto himself!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
be a law unto yourselfbehave in a manner that is not conventional or predictable.
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