I don't understand myself?

I am exactly like you. Finally i know im not the only one. I am popular at school but i always feel like im never being myself. But if i did act the way i do when im alone, i would be a very depressing person. I think this is because i just focus on the reality of the world and as you know, that is depressing in its self. i do not fear death because i know when i die i will have fufilled my purpose on this world and move on. I do not enjoy sugar coating things but that is just part of my faux personality. People see me as being fun, humorus, care free and confident but im not sure if that is really who i am.