Be who you are and say how you feel because those who mind don't matter and those that matter don't mind- Dr.Sues
I think this means to be who you are no matter what person it is because if they truley care about you they won't care and if they do care there not a true friend and you need to kick them to the curb and fill your life with the people who don't mind and are your true friends because as the quote says the ones that matter don't mind
