I have no strong urge to fly and I know this because I've been handed the controls of airplanes numerous times. I also piloted Hovercraft I was part in designing and building and I can best describe the feeling as riding on snot, again, no thrills. Scat Hovercraft out of Miami once offered me a Hovercraft to pilot in races, all expense paid, but I politely declined having the skill but not the drive. I find exploring the bottom of the ocean, wreck diving or spelunking more fascinating by far. Second nature? I never considered classifying my lust for exploration as anything other than liking a change of scenery, something different than what I already know.