To be in one's most natural, comfortable, sincere, and ingenuous state of mind and being. You should always try to be yourself with those you care about. I told her to just be herself during the interview.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
1. Act in one's usual fashion; be in one's normal physical or mental state. For example, Peter's finally recovered from the accident and is himself again, or I was completely distracted; I just wasn't myself.
2. Act without pretense; be unaffected, sincere. For example, I really enjoy their company because I can be myself with them.
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
be yourˈselfact naturally: Don’t try to act sophisticated — just be yourself.
Farlex Partner Idioms Dictionary © Farlex 2017