"It's impossible for you to make good decisions."
/When I was about eleven, my mother took me to visit her parents. They were emotionally and verbally abusive when she was growing up, and she still constantly seeks their approval. She wanted to show off her golden child so that her parents would have an opportunity to find something good in her.
We ended up in a discussion where my grandfather told me, "It's impossible for you to make good decisions because your brain isn't fully developed. You'll be making bad decisions until your mid-twenties." He added that I would probably be pregnant a few times and that I would borrow (and owe) him money between then and brain maturity time.
He was wrong, but I still remember him saying that.