Question all the things.
Question the Reason of Questioning.
Honestly, if nothing on earth convinces you, and everything is just one huge collaborate conspiracy to invent a mentally retarded guy, who worked like a info vending machine.
I have one final question. If such a savant exists, would you travel to his location and question him in person?
For this unreasonable burden of proof you demand, would you carry that stone yourself, even if it is so heavy that god can not lift it?