We need to have a positive image of ourselves. We should cherish our values. We should feel good about ourselves - our thoughts, words, and actions. Only when we see a positive view of our inner self will the same positivity be reflected to the outside world. Feel good inside. Don't think less of yourself.
But, viewing ourselves positively is 1 part of the story. We should not be obsessed with our story only. Life is not about ourself alone. It is about people around us. How much we are involved with others, how much we reach out, how much our helping hand is there ! For this to be there, there must be less "me" and more "we". Think of yourself less.
So one of the lessons of humility is :
"Don't think less of yourself, think of yourself less"