There are no known writings of Jesus. I'm not aware of anyone who ever claimed there were. I'm not sure why that's important. Are you suggesting that if there was an " Autobiographical Gospel", it would change the way you see things?
As to your statement ",,,,by people who never met the guy...", the apparent Gospel writers were Matthew, the Levite, Mark, Luke and John. Matthew and John were disciples of Jesus, Mark was a contemporary, Luke, (possibly a gentile, but intimately aquainted with Jewish life and practice), was the one who did not meet Jesus, but did know many of the eyewitnesses. Of course, you can say that later people made it all up, (thought you don't have a lot of years to play with before extant manuscripts start popping up to ruin that game). I grant that the authorships cannot be "proven," (which is true of every ancient author from Herodotus to Moses to Hillel), but you are in error to reason that "therefore the claim is false."