The idea that virtually nothing in life is actually derived from first principles, and is instead derived from sometimes very random history, would probably deserve to go near the top of any FAQ for life. Might be one of the most common misconceptions in the entire world, the idea that somehow, some way, someone had to have created things the way they are intentionally, for specific reasons.
Instead of things just working out this way because of a handful of barely-related decisions made by basically random people here and there through history, and everyone else just going along with it because they mainly just care about their own lives, who they’re dating/marrying, what job they have and what’s for dinner tonight, far more than they care about the voting age.
Our world is far more haphazard than planned, overall.