You've dragged Joly into it anyway, Bahorel. He hums over his croissant, thoughtful. "-- It's true, of course, that people tend to seek out work that suits them; when they have the choice of it, anyway. But, you know, I have known men who went into medicine when they couldn't bear the sight of blood. Some of them overcame their old aversion, in the name of the work they wanted to pursue. Others never could." This is just thinking out loud, bouncing ideas off his friends to knock some of the rough edges off the thing. "The difference there--I don't know what it is. I'm fairly sure it's not just willingness to change, or even the strength of the initial aversion."

That some habits change easily and some don't is of course an obvious observation--but the Why and How of it still matters, if education is going to be useful to people at all. Obvious has never meant simple.