My wife and I were talking about something similar while walking the dog this morning. I'd said 60 was the new 40; she said there are still a lot of ways aging can and does kill you, like Alzheimers (her mother died of it). I responded "but they're working on that."

Then it dawned on me: These days, an integral part of our mental framework is the dollop of optimism that comes with "they're working on that." I wonder whether people 100 years ago had the same feeling.