The idea of the mid-life crisis is not new. Many of us recognize differences in what we are doing in our lives during different decades. In our twenties we are often finishing university, marrying and starting families. Through our thirties and forties we are building careers, raising kids, maybe getting divorced, but in any case in our prime. Of course, our fifties were associated with reaching the pinnacle of a career - of a time when children leave the nest (and sometimes come back), and adults prepare to retire.

Gail Sheehy wrote the book Passages: Predictable Crisis in Adult Life in 1976. She was a journalist who examined the psychology of the major stages in adult life. She added case studies and revised her book into "New" passages later, to reflect changes that were not apparent to her in the 1970s. The biggest change was that people in western societies were living longer.

If we are now more commonly living into our 90s and 100s, with many of us vital and active, sharp of mind and continuing to learn and grow, then a model that stops in our 50s is insufficient.

When Sheehy renamed her stages, she called the ages 18-30 "provisional adulthood" (perhaps a reflection of the difficulty young adults have had in recent decades to become fully independent). The ages 30-45 she deemed to be "first adulthood", 45-75 became "second adulthood", and finally, for those 75 and older, Sheehy described those years as third adult hood. (Kinda like the Third Age of Middle Earth, I suppose).

I rather like my second adulthood, thank you.

Despite the fact that Sheehy had somewhat of a reputation for making factual errors in her work, the ideas she shared have some value. She is not a scientist. The fact that she studied under Margaret Meade didn't win her any points in my book, either.

However, we all know about "mid-life crisis", menopause, and other big changes that affect men and women as they age. The whole business of expecting people to retire and step aside at 65 has come into question. Personally, I never plan to retire.

The truth is, there are decades for us to grow and learn, and maybe pass our wisdom down to those who follow. One thing thinking about Sheehy's book did do for me was make me aware that I'm not on a count down to the end of my life.

When athletes run a race, they set their sights past the finish line. They hit the finish line running as fast as they possibly can. This is the take-away I got from Sheehy's ideas. Yay! Second adulthood! Whoo, hoo! Third adulthood. I can hardly wait.

So, what about you? How would you map out your life - see yourself - if you're going to live to be 100? (Just think about it). How does that change the way you see yourself? If you knew you were going to live to be 100, would it change the way you live your life?