No, she said she’d come across it in a book she’s reading. It does sound Yogi-ish.

The idea is that in a relationship each person knows things about themselves and the other person that the other person doesn’t necessarily know about themselves. So only by communicating with the other person can a person know themselves. So you say can’t “I’m a good mother” all by yourself, other people have to know that about you too.

I brought this on by making my closing quote the Delphic maxim “know thyself” (γνῶθι σεαυτοῦν).