I had a similar thing happen a little over 10 years ago when my grandfather set up a trust for his children and grandchildren before he died.
A couple of the grandchildren had only met our grandfather a few times and some only once.
Watching the family dynamics since then has been interesting.
It hasn't been stupid money but I guess it's been enough to live on if you lived frugally. Unfortunately unearned money doesn't get spent that way.
I've tried to save and spend wisely but that's not as easy as it sounds. Just look at the engine in my 930
Either way, I'm very thankful especially because our grandfather still had fun with his money when he was alive.
Good luck!