My brother was born when I was nine years old. My parents had all but checked out of the whole child-rearing thing by that point, so everything from changing diapers and making bottles to homework help and driving lessons fell on my shoulders. This was in addition to the cooking and cleaning I had to do around the house, since my parents were either too lazy or too drunk to do much of anything outside of their jobs... and my mother wasn't very motivated to do that.

This would be repeated several years later with my sister, who is actually a fine parent, but often overwhelmed with the amount of work she brings on herself. She and my brother-in-law were living with us at the time. He's from Canada and went to school in the States, so his driver's license wasn't valid. So I had to drive my sister to the hospital at 2 in the morning when her first was born. Cue many more days of diapers, bottles, etc.

I've already been through every step of the child process, aside from the act required to make one. I don't hate that I had a hand in raising these various family members, but I have no interest in going through it again. Besides, if I were to meet someone and try now, I'd be well in my 50's before they graduated high school.