Well, the Universe started(or at least estimated to start) if the first trillionth of a second, so, by the time you get there, the Earth is a sea of lava and galaxies everywhere already are in some sort of shape... But, if you saw the big bang then well... You die of old age. (Yes, this has already been said before. I just had to say it again.) I go back to 19_ _ to see myself getting born.