Two Rules for Adding Backstory.
The first rule is the 'Packing for Tahiti' rule
which is to say
you don't need as much as you think ...
because mostly you'll end up swimming along fine
and wrapping a towel around you when you get out
you can just go naked.
(and this might only apply to me and my tendency to construct silly and complicated plot lines)
if you find yourself having trouble slipping in the backstory,
then maybe you should reconsider
the very existence of
Do you need all this who-struck-John complication?
But then, with me, the need to reconsider my backstory
strikes with great frequency.