I think that Ki just IS. You can't explain it.
Many of us know how to drive a car. But few of us can expertly explain how to get the metal from the earth to build it, drill and refine the gas that fuels it...but most of us know how to us the KI that is present in it and drive it down the road. And THAT we can teach to others!
It's not important to be able to explain KI, just important to know how to use it and THAT is why we have teachers to teach us!