Is 40 Really the New 30?

Cheer up, ladies! you are not as old as you think. You may have turned 40 on your last birthday, but you're not actually a day over 30.

An international team of experts has redefined what it means to grow old. The new definition: It's not how long you've been alive that counts, but rather how many years you have left. As life expectancy has lengthened, the whole idea of middle aged has shifted, making 40 the new 30. And 50 is the new 40.

It's true! People who are nearing retirement are as vigorous and healthy as middle aged people were a century ago.

Do you seem younger than your parents were when they were the age you are now? It's not your imagination. In many ways, people today act younger than their parents did at the same age. And that is because of our psychological shift in judging our age not by how long we have lived but rather by how many more years we have to look forward to on this Earth.

Credit this to the new math. As people have more and more years to live, they have to save more and plan more and they effectively are behaving as if they were younger. A lot of our skills, our education, our savings, and the way we deal with our health care depend a great deal on how many years we have to live.