[keiferski]

I think you completely missed the point of his anecdote. It’s not a scientific study, he is merely saying that at age 9-11, you’re old enough to have a decent understanding of what you’re interested in, but not old enough to start worrying about social and financial pressures and expectations.

And so the thing you were interested in at that age is probably similar to what you’ll be interested in now, if you remove social and financial expectations.