Even in grade school I knew this was hogwash. I didn't act the same in class as during recess, or in church as when at the dinner table. Exactly which me was I supposed to be? When someone asks, "What am I supposed to do?" They are really asking, "How should I behave?" And if you've never been on a date before, or this is your first job interview, then it's not obvious.
A: "So, how did the interview go?"
B: "Not so well, he threw my resume away, in front of me, and ordered me to leave."
A: "What? Why?"
B: "Well, I did just as your said, I was being myself. I walked in, gave him the ol' finger guns, then started with my best fart joke."
A: "Why the hell would you do that at an interview?"
B: "Because that routine always slays in the dorms and I was trying to be myself."