Who remembers the pre 911 days when a passenger could ask the flight attendant if they could visit the flight deck once above 10,000’ and almost always get permission?
I recall many times sitting awestruck in a jump seat or huddled elsewhere in the cockpit enjoying the goings on.
Once I flew from Miami to JFK at night on a deadhead flight. I was injured while diving in the Keys (bit by a Morey of all things) and was miserable and needed to go home ASAP. The airline put me on the deadhead. I was the only passenger. I spent the whole flight above 10,000’ up front. I was a pre-student pilot at that time.
I would tell the FA that I was a pilot/physician. Not sure if that helped but would provide an inkling of an idea I would be able to behave and appreciate the privilege.