Waxing exisential

I'm in Orlando today at the Florida Association for Speech Pathology giving a talk on Primary Progressive Aphasia. I arrive at the airport last night and pick up my rental car. The man at the counter asks me a seemingly innocuous question that sends me into a tailspin:

"Are you just yourself?"

On the face of things, I certainly understood his message. He simply wanted to know if anyone else would be driving his company's Ford Focus. Yet, his question was in fact existentially complex, and it kept me up for most of the night.

Could I possibly be more than just myself?... probably not.  Could I be less than just myself? ...probably so.   Am I just myself? -- I don't know.

I should be prepping my talk right now, but this question is haunting me. That's Jean Paul Sartre btw -- He seemed apt here.