But there is no way to guarantee this when creating a human. I mean not just environmental but genetic factors or those outside your control could throw a spanner in the works. It is hard for me not to think this is at some level a story to stave off the chaos of reality. If happiness was a tangible force I would be in complete agreement. But we know it is simply down to brain function.
Seeing family members with dementia brought the robotic nature of life home to me more than anything. I also knew a guy who had a head injury and his personality completely changed. Who was the real him, the old person or the new?...the actual answer is neither.
We are all just slaves to our brain wiring and our identity a construct of brain function. Knowing I don't really exist on a true level you can point to is spooky and not something I have a great urge to pass on. I actually worry for anyone just reading this who hasn't really thought about it before, sorry if I just uprooted your reality.
Anyway, as an alternative I adopted a dog, it was already alive and I know I can (hopefully) create a happier existence than it may have had. However as far as I can tell it is also in blissful ignorance of it's overall place and predicament. This I can live with and I also get some selfish happiness firing in my brain from interacting with an animal so blissfully unaware. This sits better for me than creating someone who might be blissfully unaware like the dog for 15 years but then inevitably can't be sheltered from existential crisis and reality forever.