Right on. From watching my pets, I know that when they're healthy, happy, and bored - they will start doing lots of random shit "for the hell of it." Same applies to humans, and often to apex predators. Perhaps we're too deep in our bubbles of overwork and self-actualization to remember the entire concept of free time and doing random shit just because.

I know at least some humans around me began smoking because they like the taste and, particularly, the smoke swirl.