Nathaniel Branden said this quote
“ One of the great self-deceptions--and one of the great foolishnesses--is to tell yourself, Only I will know. Only you will know that you are a liar; only you will know you deal unethically with people who trust you; only you will know you have no intention of honoring your promise. Whose knowledge or judgment do you imagine is more important? It is precisely your own ego from which there is no escape. ”