O most small fault,
How ugly didst thou in Cordelia show.

– William Shakespeare

King Lear, Act 1, Scene 4. Lear is beginning to see the error of his foolish ways in punishing Cordelia for the "small fault" of refusing to flatter him. It took Goneril being nasty and cold-hearted to him to realize this. The road to self-knowledge and from blindness to insight is proving a painful one for the stubborn Lear.