‘Forgive, O Lord, my little jokes on Thee, and I’ll forgive Thy great big one on me.’ So chided Robert Frost.
Self-Deception is complete because there is no deception at all.
That’s The Joke. The great big one.
But there’s a big difference between reading it and realizing it. Same as between hearing a joke and getting it.
‘Like Silence, like Poetry, like Prayer, a joke is not to be explained. If you explain the joke, by that very act, you destroy the joke. And what you have explained is not the joke.
But if you understand, you laugh’. [And just as often, weep.]
From the Preface to the Print Edition 
A common misconception of the line: ‘Self-Deception is complete because there is no deception at all’, a particular failing of the very intelligent, is that this is some sort of ‘Hiding in Plain Sight’ situation. It is not. Nothing is being hidden and no one seeking to find it.