This is my observation on how we are raised by adults but are eventually forced to raise them. We still help life during death. Thus, old can't exist without new and vice-versa.

Two sides of a coin
New and old
Without old, new dies

An oak tree stands proud
For what it creates
Stands firm in the ground

Alas, the old can't live
Without the new
For the old grows fragile
In the trial of time

The oak tree that once stood proud
Has now hit the ground
And the new are now old
and the fallen will nurture the new

The fallen will provide shelter
The fallen will provide food
The fallen will provide fire; an inspiration to all