Usually the context of “be you” or “be yourself” is in comparison to others from what I can tell. No need to be a copycat, don’t get sucked into that. Yet in many respects God calls us to copy or imitate Christ and even others as examples that have gone before us in the family of faith and adoption.
And how can we be truly original anyway with all that genetic and behavioural information that can serve us well just as much as undermine us. No you are not just like your mother or father or brother or sister or doppelganger, although similarities and differences may exist for God’s good reasons.You are unique!
In this we are all different with different personalities, likes and dislikes. But none of these things can be used as an excuse to not walk in God’s ways in which we all fall terribly short, each in our own way.John 12:41-50.
Learning to be you takes time as does learning to be like God and trusting in His Spirit to do the work He said He would as we are all called to walk in obedience. Meanwhile this demanding world is very often telling and suggesting as to how we should live life with its phony ideas of success and happiness and what it claims matters the most.