I would instinctively say “30’s”, as the time of having young children, and in the context of the question, I think its the “right” answer for me.
But I am more nostalgic for individual things from my childhood. Not necessarily being a child (actually had a pretty rough childhood - would not want to re-live it for any amount of money), but things of that era:
My favorite two candy bars, Marathon and Milkshake, are no longer made
Buying LP records and poring over the liner notes and art work while listening to the album straight thru at least twice.
My local Dairy Queen (its long been torn down and I moved away any longer ago). It was more like a drive-in from American Graffiti than the current incarnation of DQ. It even served pizza, which I remember as being delicious, though I was a kid who probably didn’t know good pizza
Waiting for the afternoon paper to find out the score of a baseball game that happened on the west coast, long after my bed time (this sounds ridiculous in the light of today’s technology, but it was something I looked with great anticipation)
When a Coke was a once-in-a-blue-moon treat
Looney Toons. I like plenty of modern day animation, but still consider this the gold standard of funny cartoons
There are certain toys from childhood that when I run across a youtube video for an old ad, it just my hits my nostalgia button a certain way.
There are lots of things I like from my teens and twenties that I still like, but “nostalgic” isn’t the proper adjective.
@olperfesser I thought about that. But then i remembered how much i slept (i.e. little to none), and opted for “before kids”. Actually right now (just into “empty nester” stage is pretty cool - we’re DINKs again, and still have the love of kids, but without as many responsibilities.
Mostly the late 70’s and early 80’s when I was in grade school. Thankfully I’m in a position now to bring all that shit back My daughters’ first console was an Atari 2600 which she thought was the best… until I showed her the Apple ][e. It’s important to teach the classics.