They would either be twice as wise, or twice as senile.

I remember reading a National Geographic article once about people who were well over 100. Some were in the range of 115, and some even claimed to be as old as 130. Most had a great outlook on life and were happy to be as old as they were. But I remember this one woman from South or Central America somewhere who kind of resented it. She said her life had always been hard, and the priests had always said that if she lived her life the right way, someday Jesus would come to take her to heaven. She was a little pissed off because she was ready to go when she was 70, and now it was like 40 or 50 years later! When the hell was Jesus gonna come to take her? She must not have done what she was supposed to do if she was cursed to live all those extra years!