>In retrospect, I'd say a better thing to do with a smart kid is to convince them that they should work on things they're not as good at. Nobody's good at everything. However, that would have required individual attention of a sort that wasn't available back then.

Yes and no. On the one hand, there is a lot to be said for ensuring a balance in learning, making sure that everyone has basic competence in a number of things, and exposing children to things they might not otherwise encounter and might really like.

On the other hand, if you look at achievement among adults along basically any kind of axis you find that success generally comes from extreme interest in and specialisation in a small number of things. There has to be an age and a level of basic general competence where we recognise that it is sensible for child to follow the things they are most interested in.