There are many ways to think about life as a whole.
Think about the way the stretch of the duration of a person's life can be split into stages, or you can say it's the way the mass of all people can be seen as being in large groupings by age.
Here is a simple grouping for our times.
Three groups:
aged UNDER 30
aged 30-60
aged OVER 60
(Comment: Which class are you in? )
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