David Livingstone Smith cites the following thinkers who understood how suffocating self-knowledge is. They should have been around in the second century to tell the gnostics a few things.
Immanuel Kant: The “hard descent into the hell of self-knowledge” results in the “gloomiest melancholia”.
Wolfgang von Goethe: “Know thyself? If I knew myself I would run away.”
Mark Twain: “Man, know thyself, and then thou wilt despise thyself, to a dead moral certainty.”