Eliezer, in an edit, just reminded me that Tom Riddle is 65 years old. And from there I got to looking that other ages. Dumbledore is 110. Bahry One-Hand and Mad Eye Moody are each at least ~120. From chapter 39, I got the impression that 150 years old is uncomfortably old (maybe 90 in muggle years) and 200 is unthinkably old (110+ for muggles). So now I'm confused again.

Where are all the old people? What would family trees look like if people really lived to be 120+ regularly? If you're a child you've got two parents, and 4 grandparents, but what about the 8 great grandparents...and the 16 great^2 grandparents...32 great^3 grandparents...64 great^4 grandparents... 128 great^5 grandparents...256 ...512 etc? Plus, imagine the number of children each couple would have if people jumped from 40 fertile years to 80. I could buy that with older ages, people would wait longer to have kids (In canon they mention that it was slightly unusual for people to be having children at 20 years old). That would explain why there aren't 7-10 generations of family at the reunions, but on the other hand, I wouldn't expect Wizards to be big fans of birth control or abortion. Plus, that doesn't explain where all the grandparents are.

So many things don't match up. In retrospect, it seems odd for Lucius Malfoy to be alone in front of the Wizengamot when he ought to have four grandparents roughly Dumbledore's age and two parents at around Voldemort's age (though canonically his father dies of an old age disease prior to 1996...what?). That hearing doesn't seem like the kind of event his family would skip out on. The bureaucracy and government structures don't make sense either. When I first read the story, I thought the Ministry and other power structures were dominated by old fogies, but now I realize that they're damn near children! Plus, education for 7 years makes no sense if you expect to live another hundred; muggles spend 1/5-1/6th of their life in education, but wizards only 1/15th. And heck, how does Harry go to his muggle relatives when he ought to have dozens of still surviving wizard relatives up higher in the family tree?

I suppose the real answers to these questions is that JK Rowling didn't think through the societal implications of living 150+ years old and HPMoR adopted it rather than having to overhaul the entire canon. But that's not quite a satisfying answer. So, can anyone think of any thoughts or theories on how the magical world looks the way it does with regard to age? I'd rather save my suspension of disbelief for birds of fire and talking hats, not have to spend it on census statistics.