I love all the pleasantly deep answers in this thread.
For my input: I'm everything I ever was, all at once.
You know how lenses refract over each other at the optometrist? Or how colors combine when you stack transparent cups in the washer? That's me. I have parts from everyone I ever met, and parts from everyone I ever was. There's no mask, even if I focus on one part of the mosaic in a meeting vs. another when I nerd out w/ a buddy -- it's all equally me.
I'm not Shrek though. Onions have layers, but I'm prismatic glass, chips and dips and all.