Gail Sheehy wrote a book called "Passages" that came out in the 1970s.
Most of us are familiar with the ages and stage of babyhood, childhood, and the teen years.
What I didn't know "then" was that as we mature/age, we also go through stages and phases. I think if I had been better prepared for some of them, I would have been less unsure of my sanity during some of those times.