is oneself

Verb

be oneself (third-person singular simple present is oneself, present participle being oneself, simple past was oneself, past participle been oneself)

1. (idiomatic) To behave or act naturally, without regard to how this behavior is perceived by others.
   • All you have to do is be yourself.
2. (idiomatic) To be as one usually is, as opposed to being sick, depressed, etc.
   • What's wrong? You're not yourself today.