I wonder—if an underwater civilisation were to arise, would they consider an open-air civilisation impossible?
“You’re stuck crawling around in a mere two dimensions, unless you put a lot of evolutionary effort into wings, but then you have terrible weight limits on the size of the brain; you can’t assign land to kelp farms and then live in the area above it, so total population is severely limited; and every couple of centuries or so a tsunami will come and wipe out anything built along the coast...”
He was learning how to cut the books. You were learning how to teach someone to cut the books, a task in which you had no prior experience. Yes, it took two people and it took longer than working out how to cut the books yourself; but given what you now know, assuming your new hire suddenly moves away and has to be unexpectedly replaced, you would be able to teach someone else how to cut the books more quickly than before.
Teaching someone how to do the skill is a different skill to being able to do the skill, and it requires a more thorough conscious knowledge of how to use the skill than using the skill does.