What makes a parent expert in deciding the best interests of his children? Question is related to parents wanting kids to be skilled at something or the other.

I don't think there are any "expert" parents. They perhaps might want the best for their kids, for them to excel in everything they do but it doesn't makes them an expert. For me, I am still learning although my daughter is already 7 years old and I am sure my parents are still learning with me & my sister. I let my daughter decide her extra curriculum on her own (her interest changes everyday) so each week, she gets to try something new. But of course, when it comes to discipline, I am quite a strict mummy.