Claudius and Gertrude are deceived
In the satisfaction of ambition, the lure of power, of lust.
The way one thinks that achieving these things will bring you security or fulfillment or bliss.
The way one thinks that doing whatever it takes to achieve one’s dreams won’t come back to haunt you.
The way that hubris can make you believe you could get away with murder.
Hamlet’s deception about the state of his mind is nothing compared to the self-deception in the King and Queen.