Respect and deepest sympathies to anybody who went through that, and found will to continue life as much as possible.
I can also add that a lot of my anxiety around the sudden loss of the child is the thought of their life being cut short. Everything that they could have experienced, all the potential -- gone. Sure, when you're in your 60's you still have lots of life left to live, but the weight of life being "cut too short" just doesn't seem like it'd feel as heavy as say, the death of a child, teen, or a young adult in their early 20's.
Obviously not true of every parent-child relationship, but when it is true, it hurts.
The daughter died around 15 years ago and any mention of her makes her father well up in tears. The father occasionally says he's ready to die and be with his daughter in the afterlife.
His wife isn't too happy about him saying such things. I just mention it to show just how much it has hurt him, and he wishes to be with his daughter .
As a father of young children I occasionally think about how I would feel if I lost one of my children. I usually don't go too far down that line of thinking before I stop. Even the thought of it all is too much for me.
At least some people grow callous in face of ubiquitous dangers. Otherwise people would not be able to fight in wars or survive in pre-modern cities where mortality from diseases now considered banal was actually comparable to a constant low-intensity war.
A lot of ancient societies did not even consider infants as people until they reached certain age, precisely because their chance of death was too high. If you experience something 7 or 10 times and most other people around you do as well, you will get used to it. We are just built that way. It sounds horrible to a modern person and may attract some downvotes, but premature death was omnipresent and, as such, probably less of a tragedy than today.
Looking at the old folk songs etc., their lyrics often do mention happy/unhappy love, or complicated relations with parents or the nobility, but rarely deaths in the family. If someone's death is mentioned in a folk song, it is often a young soldier - a valuable person (strong, suitable for agricultural tasks) whose life was unnecessarily wasted.
Plus, the societies back then were way more religious than today, and eternal life was considered a given. This is yet another thing we mostly cannot fathom today, especially hard-core engineering skeptics here on the HN, but people in the past really did believe their own religion and it helped them with their grief.
I know a few other stories like that, from that same era, ~ 100 years ago now. And I do not know any counterexamples that showed people took the loss of a child less serious back then, or that it was less of a tragedy. I can't look back further into history from first hand. But 100 years ago the feelings seemed to be much the same that they are today.
Chances are that further back in the past that you were right and that had different attitudes but that may have to be much further back.
I think it works both ways. Some day in the future, ordinary people won't believe how we, inhabitants of the early 21st century, would just somehow psychologically accept dying before turning 120.
I'm not sure about living to 120, if you could do it with body and mind of a 45 year old I'd say bring it on but otherwise I think I'd pass.