Your comment makes sense if we replace “smart” with “crazy”. Note that most geniuses are not crazy and don’t act crazy. I doubt any parents pointed to young Einstein, Feynmann, or von Neumann and told their kids not to be like them.

Also, I don’t think there’s such thing as being too smart. Worrying about that is like worrying that you will have to pay lots of taxes if you get rich. A good problem to have.