And this is where so many people go wrong. Parents are teachers too, and it's their job to teach their children how to fit into society, behave, be decent people, etc.
A lot of rules, like math tables, help you learn the basic foundational building blocks. Once you have those, you have a reference to understand more things.
School is, basically, for most of the other stuff.
Heh. My school published a list of rules which included: 'Any breach of common sense is also a breach of school rules.'
If the rules are consistent, some things can't be explained.
It is one of my main conflicts with homeschooling, the point of conventional schooling is that everyone must fit a mould and conforming to a structure. The lesson of that point is finding a way to deal with that conformity, you need to know the rules of hierarchical groups in order to break them or succeed inside or outside of them.
Would you mind editing out such name-calling from your comments here? The rest of your comment makes your point just fine.
Explaining all the rules is what school is for, basically.