I'm beginning to think that the eldest villager is a combination of excellent care and chance - some of them die relatively young even with attention and some of them make it into their 80's with no special care. I have not had any make it even into their 90's yet. Perhaps that chance increases with the length of time put into the game. However, I tend to get bored with maintenance and start a new game instead. Baaaaad game parent, baaaad.