Hi and Welcome!

The part where the waitress tells you you've been here before and you don't remember could be your subconscious trying to tell you that you are stuck in some type of behavioral pattern that is detrimental to your personal relationships. Or you are consciously aware of it but repeat the behavior anyway. Even though you feel the argument with the friend may not be related to the dream, the reason for the argument may offer a clue here.

Do you feel "strangled" by any of your personal relationships, either at home or at school?