Both my W and I "say" things like, "Don't sweat the small stuff." and "Choose your battles."
The "Choose your battles." came up in counseling as something one might say to a child. The MC agreed when my W suggested that, during a session.
Personally, I believe that mantra, whether for children or ANY conflict.
I generally let things roll off my back. Most things don't stick. When they do stick, it is usually when the conflict escalates and becomes more an argument over who's "right" or "wrong".
I generally do not feel I need to be RIGHT. Although when I feel I am being made to be WRONG, that is when I dig in. I prefer to use the phrase "Agree to disagree." It makes no one "wrong". It invalidates no one. I have issues with feeling I'm being invalidated, even when that may not be the intention.
I need to recognize that in myself when it starts to come up and allow myself to recognize that the opposer may not be trying to make me wrong. Rather, they are simply stating a different point of view which does not invalidate my view.