This man hath had good counsel. A hundred knights!
‘Tis politic and safe to let him keep
At point a hundred knights! Yes, that on every dream,
Each buzz, each fancy, each complaint, dislike,
He may enguard his dotage with their powers
And hold our lives in mercy.

– William Shakespeare

King Lear, Act 1, Scene 4. Goneril admits to her husband Albany the real reason for cutting her father Lear’s number of knights. It’s not to do with their rowdy behavior as she claimed when speaking to Lear. But it is all to do with Lear still maintaining a power base that could threaten hers and Albany’s position. On the pretext that Lear and his knights "hold our lives in mercy," she plots to strip away whatever remaining political and military power Lear has. The duplicitous daughter, who got her father to hand over his kingdom by false professions of how much she loved him, is showing her true colors and revealing her true self.