" “I am an illusion” is self-contradictory."

It is if you don't capitalize the "I". You, Douglas, do exist, always have and always will. In your current life, you are highly educated; in another, and you have lived many times under many different "names" on this physical plane, but you are always the soul you know of as "Douglas" and that, You, your Self, never changes. "A rose by any other name..."