Most parents begin to become sickly and frail only at a point in time when their children have already become parents themselves. This means that parents generally come to live through those nightmare aspects of the Conditio in/humana to which they have condemned their own children only when it is too late. To experience these terrible aspects “in good time”, in this context, would mean: being an eye-witness to the sufferings of old age and sickness, as these become manifest in one’s own parents, early and vividly enough to shrink back from imposing these things on one’s own children, so that one rescinds any pronatal decision one might have taken, or takes no such decision in the first place.
In Fabio Volo’s novel The Road Home two brothers visit their aged father, who is slowly dying of dementia. Of one of the brothers Volo writes: “He knew that his father’s present state was the future that awaited him himself. When he looked at him, then, he saw not just ‘him’ but a ‘we’, a collective fate.”[1] – It is high time that human beings, through moral action, put an end to this grim collective fate!
[1] „Sapeva che il presente di suo padre era il futuro che lo attendeva, per questo quando lo guardava non vedeva solo un ‚lui‘, ma un “noi”, un destino collettivo.“ (La strada verso casa).
antinatalismblog 
Maybe grandparents should teach, instead of parents, their grandchildren how hard a real long-term life can be. They have enough experience. But I have met a lot of old people with a childish mind.
Congratulations for your work.