Honestly
@jaychamp all this existence stuff has been long sorted out (Cogito, ergo sum is a Latin philosophical proposition by René Descartes usually translated into English as "I think, therefore I am".)
More correctly, In order for there to be a doubt (about our existence) there has to be an entity in existence to express that doubt. All the rest follows by logic.
Well
@bunyip then there would be no you, that is pretty simple to answer.