Society in 3 Phases

Biologically, there are 4 phases we go through each with their own unique set of changes. You start off as a baby, then you become a kid, teen and finally you're an adult.
From a society's perspective, most of us goes through 3 phases throughout our lifespan. The name of each phases are descriptive enough that we can all kind of understand what they entails. The phases are:

• The learning Phase: Everything about this phase screams "learning". The child is born and he his taught by his parents, teachers, mentors and work associates. This is when we learn the most about living on this Earth and our place within society. It is my personal opinion that this phase should last a lifetime but the reality is that people often decide to stop learning after this phase is over. This phase usually ends at the age of 30 years old.
• The Doing Phase: Now that we know who we are and how we'll contribute to society it's time for us to "do" what we've learned in the previous phase. At this point, we're well into a career and we likely own a house with a family. This is also the time for us to be thinking about our future phase as well as the future of our own children. This phase generally goes from the age of 30 to 60.
• The Retiring Phase: This is the time for us to sit on the bench and let other players jump into the field of life and make a living of their own.

It's obviously not a cut and dry process. Some learn for longer through career changes while others skip the doing phase entirely... generally speaking, these are all the things that we're expected to do during our lifetime as a productive member of society. I think that by visualizing our lives in those 3 phases it helps us understand the bigger picture and plan accordingly.