I mean, wasn't she supposed to have been sixteen or seventeen when her parents went into hiding and abandoned her? Then recently in season six there's this big fuss about her having one memory of her mother? What?

Anyway, to stick to the point, it doesn't really bother me. Essentially nobody is a genius in every field (another thing about Bones that's not very realistic, but I digress again), and while brilliant science nerds may well have been taught about all sorts of literature in school at one point, there's no reason why they should remember it any more than less intelligent people would - or perhaps less, if they spent every literature class secretly doing maths problems under their desks.

And from a writing point of view it's simply to make the character more accessible - make the audience feel they know more than the character or are more socially skilled in at least some ways. Nobody likes watching a character who knows literally everything, or is overly perfect in other ways.