My parents seem like a tame version of your parents. Probably significantly tamer but in the same mould.

Quite.

One is that when I was a toddler, she put me in one of those things where a baby learning to walk is held vertical, and then it has wheels on it.

I also had a walker. I remember corralling the dogs in the hallway and running at them full speed. This was the game. Apparently my father knew I was safe because the first time one of the dogs tried to bite me he smashed it across the face until it yelped and cowered in the corner. Then the dogs knew that they weren't allowed to bite me.

Who leaves a kid to roll down the stairs or unsupervised in a bathtub?

My mother liked to relay her solution for when I was crying too much: child-proof the house, lock yourself in your room, and wait for the baby to fall asleep from exhaustion.

My mom was never on time to pick me up from anything. It was so embarrassing.

I was a latch-key from the age of six. The last parent-teacher conference my parents went to was kindergarten. I was never so much as walked to the bus stop.

My parents fought, but I don't have any frame of reference for it. Just, it was obvious nobody was happy.

My mother would threaten to kill the dogs. Usually took a couple hours. About an hour or two later she'd go hide the cars. Grab the keys, tuck 'em up other people's driveways, dirt roads'n'shit. This was usually the time my father would say "whatever you do, don't get married".

As for my hobbies, they seem mostly supportive of my hiking.

My father forbid piano music to be played in the house. As soon as I left, they bought a piano. My mother never got a handle on what my degree is in. It's the same degree as her (now ex-) husband.

But they don't understand my running or how important it is to me.

My father knows I'm pursuing watchmaking. Sunday he regaled me with the story of the watchmaker in Brazil who also had a refrigeration company.... and my dad needed a refrigerator. The guy left to answer a phone call and my dad took the white silk handkerchief with the watch parts on it, folded up the corners and shook it. When the watchmaker came back, understandably horrified, my father castigated him for being upset because "it'll only go back one way." The guy sold him a refrigerator, probably to get him the fuck out of there. "The things some people charge money for."

If I ask about their dogs, they'll tell me how they're doing but won't ask about my cats.

I invited my father out to visit once. I was living about 90 miles north of my sister, who had just had a baby (her second). He said "well of course I'll be coming out soon, I have a brand new grandson!"

My daughter was 18 months old and had never met her grandfather.

He bought my sister tickets to New Mexico instead.

There are people with fantastic parents, right? With great memories of childhood they look back on fondly as adults?

I know them. I've hung out with them. I lived with some for a couple months. My best friend's dad taught me to drive; his mom was the one who asked me what I wanted to be when I grew up.

Everyone's got conflict. Nobody's perfect. But yeah. There are people out there whose parents don't pick their kids up off the couch and throw them across the room when sibling squabbles disturb their hangoversleep.