When you have it all figured out, this is a clear sign that you are deluded. Later, you will realize that you were wrong. You had fooled yourself. And now you have found the truth, at last.
When you have found God, when you know what he wants from you, or, if you have found out that there is no God, when you understand what life is all about: money and social status, to eat or be eaten, or, when you have found your true self, then you are mistaken.
When you know what political or philosophical system is superior, then you must ask yourself: could it be that I have got the wrong end of the stick? If the answer is no, I am right, then you can be convinced that you don't see the full picture.
However, sometimes you are right, New York is not the capital of the United States.
I have lost friends to religious and spiritual cults, and I have lost friends to political convictions. And I have had friends who have lost me because of my crazy ideas.