When Lear subjects himself to his daughters, his Fool remarks that he might has well pull down his britches and let his daughters whip him. He is no longer acting like a father; he has become a child in the hands of Goneril and Regan.
At the end of the play, Lear is in the same position with Cordelia. He wakes up acting like a child, a “foolish fond old man,” ready to run away with Cordelia and spend the rest of his days spying to find out who’s in and who’s out. He’s still a child, now in the hands of a kind mother.
Gloucester goes through a similar reversion to childhood, putting himself into the hands of his son Edgar.
The child (as Wordsworth said, in a different sense) becomes father of the man. And perhaps this is the movement of every life – every son is destined to be mighty father, every father moves toward new childhood – and perhaps the movement of every asymmetrical relation – the disciples becomes like his teacher, begins to teach the teacher.