Keep in mind that a child’s brain is incapable of leaning certain things before it develops enough. While hard and tedious repetition may seem to work, opportunity cost is horrendous.
My last kid is off to college as a pre med major in about 6 weeks. I basically did the opposite of all of the hard charging, teach your children everything, get your children ahead things that you see promoted here on HN. Mine were free range and breaking bones and getting deathly sick and etc etc etc. But you know what? None of it killed them. They found things they were interested in, and curiosity did the rest. They just had the regular problems. Girls used to be involved in petty high school dramas that would make Shakespeare look stoic for instance. But all in all, they turned out well.
I really feel bad for the children of some of the people I see posting on HN regarding child dev.