Dr. Seuss Quote?

I was a little sad when I saw a quote on Pinterest that was attributed to Dr. Seuss. It said "Be who you are and say what you feel because those who mind don't matter and those who matter don't mind." An internet search told me it was actually said by some old presidential adviser named Barnard Baruch.

I'm very glad it wasn't Dr. Seuss. It just didn't sound like him. To say that some people don't matter? That's not the feel I get from him. And it's not what I believe. Everyone matters. No matter how poor or meek or young. I guess I just don't want to believe that I don't matter.