I confess to not having read every single post.
When my generation ranged in age from late-20s to late teens (I was in the middle of this range), a great-uncle (my paternal grandfather's brother) who had never married left everything to two of my cousins (brothers). The other four cousins (brother and me, and two other cousins) were related through our DMs, who had taken their husbands' surnames on marriage. So we, the DCs of those marriages, had our DFs' surnames. The two male cousins who inherited were related through their father, my uncle, and had the same family name as the great-uncle who died.
My mum and aunt speculated at the time that the estate had been left "to the family name", but we'll never know if that was the actual reason. The brothers who inherited were the oldest of all of us, so it's possible the will was written after they were born but before the rest of us were. However, as the youngest cousin was at least 16 at the time, there had obviously been plenty of time to update the will if great-uncle had wanted.
My DM is pretty sure that her dad would have been horrified that his brother, having chosen to leave his estate to his brother's DGC, hadn't split it equally between all six of us.
DM said that if it had been DBro and me who had inherited, she'd have strongly urged us to share with our cousins. Easy to say, of course , though I think my DM would genuinely have thought that fair. Our cousins did not share with us and each ended up with £100k+ once the house was sold.
It was a bit odd and a bit disappointing, and generally just a bit weird to know that two of my cousins got this massive start in life and the rest of us didn't.
We're all spread across a few different countries now (two not in UK) and I have barely seen most of my cousins since the last one of us got married. The one exception is one of my cousins who inherited. I don't see him often, but we have a good relationship. If he lived nearer, I'd see him more often because I enjoy hanging out with him.
Although I occasionally think about the oddity of it all, I don't feel hard done by. It all happened over 25 years ago now but, even at the time, it wasn't money I was expecting so it wasn't as if something had been taken away from me.