But I'm convinced there is a yawning gulf between us.

Tops and marbles weren't just a Cuban thing, they were a kid thing. The ones in the image are identical to the ones my friends and I played with, I found the pic on an antiques web site.

The only cultural watershed I can think of is the introduction and propagation of television. I was on the cusp. I first saw TV when I was 4 or 5, my Uncle Frank in Tampa had one, but only because he was an electronics hobbyist, the only stations he could pick up, even with his monster DX aerial, were Jacksonville and Havana, and then only when the atmosphere was just right. My grandfather had one when I was 7 years old, I remember walking miles with my parents through the snow (we lived in NYC at the time, 1954 or so) just so we could watch Ed Sullivan, Lucy & Desi, and the Friday Night Fights. I used to really get upset because the grown-ups would never let me watch Disney because they wanted to watch their own shows.

We didn't have our own TV set at home and I didn't watch one regularly until around 1958 or '59. I remember listening to radio drama. I remember my relatives in Cuba had a TV set when I went to visit there in '58.

I suspect TV changed everything. When broadcast commercial radio came out in the 20s and 30s, it took over gradually. TV took over suddenly, and the baby boomers were snagged immediately. Being born in 47, I still remember pre-TV times. or at least, the time before TV became a standard home appliance.