How bad does it hurt to catch a foul ball or home run?

I've been to probably 20 MLB games in my life, and have "caught" one foul ball (it bounced and then rolled under my seat), but I always wonder how it feels when fans catch those high exit velo balls with their bare hands. That shit has got to hurt right? It happens a lot every game, sometimes you see absolute rockets go into the stands, but rarely do you see anything about people breaking fingers/hands catching those. I know there's those freak stories of people getting hit in the head and having serious injuries, but I'm talking about the routine balls that go into the stands. Does anyone have any experience with it?