Have you ever wondered why you say the things you do? Do you ever stop and think "where did I first hear this?"

I posed that question to myself today after saying my new phrase about four times in a row. I call it my "go to phrase" - when I don't know what else to say, I say "Zero F**** Given." I'm not sure where I heard it or why I say it.

What is a phrase you say all the time that you aren't sure exactly where you first heard it at?