As someone without the human instinct to reproduce that 99% of all humans seem to experience, it has always felt a bit like I am an alien from a different planet. Or like I am born without one of the lesser senses or something.

You're not. Or you're not alone.

My spouse and I (50+ year-old) have been together for 25+ years and have no children — be it by making them the good old way, or by using some medical help, or by adopting them (to remind the OP there is more than one way to 'reproduce' as human beings).

We never had any drive/urge to have and raise children, so for us it was a question we tried to answer in a calm and non-emotional way: will we or will we not have children? Also, we were still a young couple when we realized the absolute shit world they would have to live in as adults, which did indeed help us a bit in deciding to not have children.

25 years later, I don't think we ever regretted it. But, who knows, maybe people like us do indeed lack of something important? I doubt it, though.

But thanks for this. It was an interesting read.

You're more than welcome.