"I know paper can be made from leaves, or old paper... but I don't really know how."

Oh, sure, every kid has that 'recycling old newspaper' science/art project in school, but it's been a long time for him, he's learned other things since then that he needs to use more. And making paper from leaves, well, he just has no idea. (There's also making it from trees, but he doesn't want to cut down the trees and he's not sure they have the means to do so anyway.)