Two answers for the price of one. The first is philosophical ***, the second, is better. Philosophically you would not be interested in the truth, so here goes. Wether you would know it depends on wether there is a God and an afterlife. If there is, then you would most certainly know something (check out a book by a neurosurgeon who had the esperience-Proof of Heaven), if there is no God or afterlife, then once your neurons shut down you know nothing, no thinking, no memories, no senses of any type. Okay, now for the Truth. Law-matter cannot be created or destroyed, and yet it is here. Proof that something impossible happened. Life comes only from other life, so that fact that anything is alive, is also impoossible, a second impossible thing. Only God can do the impossible, so God exists. You may not remember this existence (see book mentioned above), and you may or may not know of a previous life, but you will know that you are. There are many things we cant see, feel, or touch as we might like but they still exist. God is so obvious isf you know how to look. Believing nothing exploded and rock soup became living stuff that we all somehow evolved from takes alot more faith than God