Another reason why I’m not fond of the Harry Potter world.
As near as I can tell, if you grow up in the magical world (as opposed to be Muggle-born, for example), you do not go to school at all until the age of eleven. In fact, it’s entirely unclear to me how the children of the wizarding world learn to read and write. There is a reason Hermione seems much more intelligent than Ron Weasley. It’s because Ron is very likely completely uneducated.