Yeah, MMario hit it right on the head there! ;-) We were a generation with rather odd expectations when it came to aging...
Everyone feels immortal when they're young. My theory is that that is because the human soul IS immortal, so to feel immortal is natural in people...and in animals too...because animals likewise have immortal souls. Everything has an immortal soul, in my opinion.
(and it's strictly my opinion, so don't sweat it if you think I'm wrong...it doesn't really matter which one of us is right or wrong about something like that) (so we don't need to argue about it)
Now when an immortal soul finds itself in a body that is aging and wearing out...it's not comfortable with the situation. It's frustrating, it's often discouraging, it seems to fly in the face of everything you instinctively feel about your own identity.
We don't believe we'll die, because we don't die. That's my opinion.
But our bodies sure as hell do. I will be quite willing to "go" when this body has become unviable, because I will regard it as personal liberation to go at that time. I am not this body. I'm the occupant of this body. When I'm gone, you'll know it...if you're there to see it.