i know so little

I feel the twinge of
sciatica
run up the back of my leg
from heel to spine.
I cringe at the numbness
and tingle
of it burning.
it's not old age,
or stress,
or weight, it's just
the nerve
impinging on some unseen
bone, or muscle,
ligament
or something I know nothing
about.

there is so much I know
so little about.
but the things that I do
know,
I know thoroughly,
without a doubt.