The Human Lifespan
When in the womb, a foetus is very firm in order to grow so much, and doesn’t have that many other characteristics. In early childhood, their characteristics flower in all directions and so their personality comes into being. Until around 5, all their qualities come from their mother, and from around 6 they start learning qualities from their father. The father is then increasingly important until the age of around 15, when he is incredibly important for stability, and the mother is quite important for the same thing.
Then the person starts to become independent from their parents. The next 15 years of their life are spent developing their adult qualities, such as work and marriage. At the age of 30, ageing starts. This is for the simple reason that their parents don’t love them enough to keep them so firm. This means that materially they become less firm and more normal for the natural world. This continues for the rest of their life. The rest of the details of ageing are commonly known.