Comment by rvp-x

Not noticing doesn't mean the world doesn't care. There are a lot of reasons people vanish and it's harder to notice the absence of something than its existence, and people usually vanish for positive reasons, so I think nothing of it. I cried after discovering some people I hadn't known personally but were adjacent to me have died. I didn't notice their absence but I can empathize with the suffering they felt before their death, or the feelings of their family coming to grip with their absence.

While I have a strong emotional reaction to it, I don't think it's a bad thing, it is a part of life and a reminder for me to savor life.