Notice that I have said please be yourself and not please yourself all the time. Know who we are as individual people and what we really need in life and require, rather than getting what we want all the time in any fashion or order is and are two completely different things. ":Please be yourself" is like knowing your God given gifts and using them for His glory. When we start to search for the real us, the person who knows what they are like and what they really want, is the real us. It is not until then that we learn to understand who we really are in the big picture and scheme of things by understanding our individual idiosyncrisis.
Getting Gods perespective for our lives is far more important than satisfying short term individual whims and fancies that just drift in and out the door or window in any fashion, shape or form. Being your self or which is the same as understanding yourself is the way to build eternal treasures in the kingdom of God, because we seek Gods guidance and perspective first, because He has what is best for our hearts and not our head in mind. He can see further down the road than we can, as we have to watch the car ahead. When we get home and do some reading, then we can get God's perspective on how to live our lives for the long term. Please understand how to be yourself or would you like to try to please see how people are capable of being themself, is a bit like a self reflecting mirror, rather that when we see the type of people that we would like to be we can emmulate them to help us fashion our own lives to be more like them.
The real hard core way to be yourself is to study God's word and emmulate Him, you can't go wrong with that. The character of God is far more satisfying and appealing than anyone else on earth. The world we live in has a lot to offer and we are all guilty of falling into that trap but we must consdier other people first and look to them and treat them as we would want to be treated by them to ourselves. We must be partakers of being ourselves, but it is not till we learn to contribute back that we can expect to take anything out of the world from that in which we live in. I hope that you might have been able to learn a little of that lesson of being yourself by emmulating the good in others and unltimately Gods character.