If we leave the world in the same state of absolute nothingness we entered it in, then our existence to ourselves does not matter. Actually think about this for a second: if there is no afterlife, you'll cease to exist in the same way you did before you were born. You won't remember your life at all, and your generation that did remember you will be gone as well. It would literally be like all your experiences during this life never happened. A total erase button on your life, especially after 200 years when family stops reading about you unless you were famous. But even if you were famous it would be like you were never successful and never felt the sensations you got to experience. Maybe this makes the case for there being an afterlife since life itself is pointless without it. I personally believe that a dead person ceases to exist completely. Do you think Abraham Lincoln remembers his accomplishments if there is no afterlife? No, he has a perpetual legacy for as long as the U.S. exists but without an afterlife how he lived his life would make no difference to himself in a state of nothingness. Nonetheless without an afterlife it would be as if all of our lives never happened to ourselves at least once we're gone. If we enter a state of absolute nothingness, then it would be as if all of our memories, experiences, and sensations did not happen. Sure, they may have an effect on a future generation but if we transcend into the plane of nothingness we originated from then our time here would feel (or not feel as we would be in a state of nothingness) as if it never happened if you can't feel emotion or remember what that life was like.