This galaxy has some planets that are used to assist various forms of life through a certain stage of their development.
This is what your writer knows as Upbringing.
Our planet has been used for this function, over and over again, for millions of years.
Races evolve on other worlds and then are brought here by a group of
races who work to assist the Progenitor race. Progenitors spark
evolutionary leaps and monitor evolutionary development of new species
and races. Once they reach a suitable point the Progenitors will ask one
of their assisting races to relocate the species to a planet suitable
for their Upbringing.
Often the race is aware of the reason for their location. At times they
are not but choose to go anyways. In some cases when dealing with
hostile races this relocation is done by force and not invitation.
This planet has everything a race could need. This is part of why our history is so confused.
Sometimes the race developing here learns to leave the planet. Typically they will move on to a new world.
Sometimes they don't. Once they have reached a point where they are no longer progressing the are moved to a new world.
When the majority leave some often stay behind if they can, although
sometimes the process required to reset the planet so she can return to
her natural state.
Same applies on other planets used for Upbringing.
We have reached a stage in our Upbringing where we are at a crossroad.
It's about time we move on. Still, there is work to be done first. We can
skip ahead and risk another cycle of control, or we can take a step
back and correct our mistakes as to avoid once again falling under the
control of others. The Choice.
Specifically, we have to become a sovereign race. In order to do this
we are going to have to overcome the Parents. This is a task we are
equipped but not yet prepared for.