By Jon LaPook – CBS News Sunday Morning

There’s an old saying among doctors: if you’ve seen one 80-year-old, you’ve seen one 80-year-old. Some will act like they’re 60 or 70, while others seem a lot older. So, instead of asking How old is too old?, shouldn’t the question be, How old is too old for what function?

“Absolutely. I could not agree more,” said Dr. Louise Aronson, a geriatrician and professor of medicine at the University of California, San Francisco. Her bestselling book “Elderhood” is about redefining old age. “I honestly think anybody who’s lived past their 40s knows age matters,” she said. “Your body changes, your brain changes. What I would like to see is a conversation where we actually discuss the things that matter.”

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