How many people live inside of you?

I was just finishing mowing my lawn and went to the gas station to refill my grill’s propane tank. The guy on duty there is one I always flirt with.
A few years ago, I led a class for pre-teens in media awareness. Two girls from my class were in the store.

I walked in as a tired homeowner, turned flirt, turned authority figure “Oh hi, Ms. Blue!”, back to flirt, then home.

It feels like backstage quick change of costume. How many people are you? How quickly can you change?