Deep question......?

Well, the best answer for me on this one is the Skeptic Theory. Since there's always the possibility that we could really not be here. We have to doubt our memories and our thoughts because they may not be real. The same goes with reality. We have to doubt that because we can't prove that either. But what does the Skeptic Philosophy teach us? That it is hopeless to continue to doubt what we see. Technically you can't prove reality but that follows the Skeptic Theory that it's pointless to doubt.