Semibovemque virum semivirumque bovem
Classical poet Ovid once asked each one of his friends to choose, from a poem of him, three verses they considered the worst and that were to be deleted; also, he told them that he also had chosen three verses himself that were not to be deleted, no matter what. When they finally met, it was found that everyone, even Ovid himself, had selected the same three verses. Seneca the Elder tells this story to explain that authors know the problems about their own works, but that they don't bother to fix them. He does not explain further if this is because creators know better or because they are arrogant boneheads.
There is a different telling of this story that says that, when everybody met, nobody had chosen the same verses; because of this, after deletion, the poem was left with only three lines, the ones chosen by Ovid. He was not upset, though, because he saw it coming: the slaughtered text showed Latin words for "My friends are a bunch of hateful motherfuckers".