At 53, I play hoops with my teenaged sons, and just bought myself a new bicycle so I can ride with my five year old daughter. They don't care how old I am, we all just love each other. There are no guarantees in life - just last week a work acquaintance, 33 years old, had a brain aneurysm while on vacation, died and left three small children. Live life and take good care of yourself.
One small piece of advice though - get a hot tub, because you may think young, but your old sports injuries will be back to say howdy!