The nature vs nurture debate makes me think of North American culture. Growing up in Canada, the majority of opinions thrown at me were: explore, have some fun, but ultimately get a career that will give you a good salary and benefits. There was a 5 year or so gap after university that I had to play with, then I felt the pressures to grow up and choose something.
I have this suspicion that European cultures appreciate art, recreation, travel, and a life outside of work more. I think North Americans love to define ourselves based on our jobs and incomes.
Maybe this is just wishful thinking. But, a culture that teaches you that success is gained through employment will inevitably cause depression/ laziness/ tv-watching zombieness when that is not being accomplished.