We have very good relationship with our neighbor, who's French (this will become relevant later). We met at the playground both babysitting our kids. We know each other well enough to come visit, eat lunch together, go to various children-related activities etc.
About a month ago, when we came to visit our neighbor, she had a guest, whom she introduced as her cousin. Couple days ago, she had another guest, and what do you know: it's another cousin! I asked how many cousins does she have. Her and her cousin started to reminiscent and came up with an estimate of around fifty. My jaw dropped. Then they went down the memory lane, recalling their childhood and how they'd spend summers in the family house: legion of kids with few adults in sight.
My father had two brothers. One had (at least one that I know of) son. The other one had a son and a daughter. No two brothers live in the same country. I've only ever met one of my cousins, once. My mother was the only child.
But this was also the very common situation in my childhood years. Everyone I went to school with barely had any extended family. And once I started to think about what might have caused the difference: well, these things come to mind: my maternal grandmother had 11 siblings. One or two died in the war. A better half escaped the Communist regime. Those who didn't were sentenced to exile in Siberia. She and her sister were what's left of the family. That sister never married and had no children.
Similar, on my father's side, a bunch of relatives died in Holocaust. And even later on, through the Soviet times, the situation wasn't conducive to having many children. My parents, already, grew up in the world where cousins were rare.
It looks though like in some places in Europe, the war didn't affect the siblings situation so much, and even my generation had a chance to meet a bunch of cousins. The US seems to be similar in this respect, at least according to my wife's testimony, who would every now and then mention he cousin who is an architect / drug addict / screwed up by 'Nam / fashion model etc. There seems to be no shortage of cousins to draw on.
Our kid, in total, has three cousins. And there's unlikely to be more. Which is a new thing for the Western world, I guess, especially the parts not so much affected by the war. But this is how things have been for at least a generation in the East.