“Every fool stands convinced; and everyone convinced is a fool. The faultier a person's judgement the firmer their convictions.”
“Nobody's easier to fool, than the person who is convinced that he is right.”
“I suppose [...] that the most convincing way to fool an enemy would be to fool a friend.”
“It's easier to fool people than to convince them that they have been fooled.”
“Feeling like a fool, he went to convince Jane to water her crabs.”
“I am not sad, he would repeat to himself over and over, I am not sad. As if he might one day convince himself. Or fool himself. Or convince others -- The only thing worse than being sad is for others to know that you are sad.”