Touchy subject. The sadness part of it partially has to do with not knowing what you have until it's gone. That said, you can't really know what the death of someone close is like unless you've experienced it firsthand. Religious or not, you know that you will never see them again except in memories. Those memories bring back the old joy. but the pain returns as well. It hangs over you for, as far as I know, the rest of your life.