The philosophic exercise of likening oneself to God in that the direction and meaning of your life is yours alone to determine. The admission to oneself that anything and everything you know to be true may in fact be false, and that you do not possess the knowledge to determine what is and isn't. The method of continually constructing personal arguments for your decisions despite the knowledge that what you do may or may not matter.
These are two conversations about existentialism.
"Do we exist solely as figments of the imagination of God?"
"Perhaps. Then is it possible that the characters of our own dreams and imagination are of a similar nature to ourselves?"
"Life is meaningless. I should skip work in the morning to drink and enjoy myself."
"No, perhaps you should be responsible. You never know when you might find out the reason why."