Is there an actor/actress who you’ve changed your mind about in a positive way?

I was not a Cena fan. I figured he was another Rock because he seemed to be following in his footsteps. I never went out of my way to watch anything he was in because of that belief. I also really didn't like his character in Suicide Squad, but I decided to watch Peacemaker and it is absolutely hilarious! The intro has me laughing every time.

From all accounts he seems to be a really nice guy and humble human being. I was wondering if there were other actors who would fit the bill besides the always mentioned ones. We hear so many negative stories about stars, it'd be nice to hear some positive ones.