The advice is almost always well-meaning, but it’s completely clueless.
“Come on,” the advice goes. “That happened a long time ago. He didn’t really mean to hurt you. They did the best they could. You just need to let it go. It’s time to get over it.”
I know what it feels like to think this about someone, because I’ve done it, too. I remember a conversation I had years ago in which a friend and I mocked someone who couldn’t “get over it” and move on after childhood abuse. That was before I understood my own childhood trauma, so I eventually felt guilty about having said such things about someone else.
But I get it. When you watch someone else go through the agony of long-term pain and anger from emotional abuse, it’s baffling if you don’t have a frame of reference. The person who’s suffered abuse can come across as crazy — at least it can look that way to someone who’s not hurting.

I choose love over hate, because the author of the story’s not done
Attention word nerds: March forth, to celebrate National Grammar Day
More dependence ahead now that half of households get U.S. checks
That huge fed debt increase? They’ve already used 60 percent of it
Insane incentives create insane results as kids are paid to attend classes
Genetics, culture work together to drive us to pursue what we want
Ignore the happy face it presents: Coercive state points a gun at you
Unity sounds nice, but truth is we need freedom to go our own ways