There is no limit to the human capacity for self-rationalization. (Chuck Colson, late Christian apologist)
Did you ever think that someone is “fooling himself/herself” because he or she refuses to recognize a weakness or they think they are better at some task or activity than they really are? But, wait! That same fault is likely true of all of us at some time or another. Taking a careful look at ourselves with the counsel of others might well prevent us from tragic mistakes.
Do not think of yourself more highly than you ought (Romans 12:3).