It could be middle age tainting my perspective... but sometimes I feel this sort of... not visceral, but very close and undeniable... experience with death is easier for people who are young.
Death isn't real for most people at 17, no matter how much they have seen, many see the death of a grandparent, or two, or perhaps even four, before reaching 17, but most still enter their late teens, feeling invincible and like death is a whole lifetime away... because on a sort of undeniable personal narrative level is is... it is a lifetime away... and things that feel a lifetime away are much easier to think about than things that feel like they get closer every year. In middle age you know your to some statistical average "about half way there"... and that's a very different place from which to begin having this kind of life experience.