Lear said, "how sharper than a serpent's tooth it is to have a thankless child." Sadly, he was referring to the good daughter, Cordelia, who was ashamed to state her love for her father, in the "suck up" manner her sisters descended to. Also, do I recall correctly that a fellow named Gloucester, who had one of his eye put out, then heard one of the perpetrators say, in effect, let's put the other eye out too, "for one side doth mock the other." Oh horror.

Further, who was it who played on Lear's "serpent's tooth line," something like this? "How sharper than a thankless tooth it is to have a serpent's child?" (That's an "extra credit" question.)