When someone is resigned to life as it is
I accept myself for what I am.
I’ve come to terms with myself.
I’ve come to terms with reality.
I’ve come to grips with reality.
I’ve learned to face the music.(idiomatic)
To face the music=to face life ;to face reality
Leave well enough alone.(cliche’)
Let well enough alone.
Let sleeping dogs lie.(cliché)
=Do not try to solve a problem that is not causing extreme difficulties at the moment.