[wstein]

Identity is of course an arbitrary self definition very subject to change.

Your inner nature is far less subject to change. The very choice of identity is largely defined by your inner nature.

Be yourself refers to acting/responding from you inner nature not from your experience or due to outside forces.

Obviously as you act, you interact with that around you. This issue is not about what you do but rather why you do things in the way you do things. Being little creatures on the same planet necessarily means there will be similarities in what and how things are done here. What make each an individual is why and in what manner one does those things.

Its not an easy thing to see clearly. To try to get a handle on being yourself, you need to track down what actually motivates your actions and where does that motivation come from. Are you doing things in a way that is in alignment of who you are or are you doing thing the way others would have you to do them? Obviously knowing who you are helps a lot in working out the answer to that question.