Could be the paper makes a distinctive rattle, and he's learned it will elicit a distinctive response. Cats' theory of mind for humans isn't all that thorough, I think, but they have a very solid grasp of cause and effect. Honestly, I think they mostly think we're simple.
They definitely aren't, though, at least not all of them. My guy used to fight like hell any time I tried to trim his claws, so eventually I gave it up and let him look after himself, thinking, well, he's a cat and he's got plenty of carpet to scratch, he'll do fine. That lasted till he got an ingrown claw, so I had to trim that back, debride and disinfect the wound it'd made in his pad, then trim enough fur on his foreleg short enough to get a bandage to stick where he couldn't shake it off.
He really hated that, for all that it only took a couple of days to heal - they're better at that than even we are, and in a week you couldn't tell except by the missing fur that anything had ever happened. Well, by that and one other thing: for the balance of his life, when I went to trim his claws, he never put up much more than a token struggle. Where before he'd fight his way to the top of my head and leap clear, this was just enough of a fuss to make sure nobody thought him a coward, and no more - he'd learned it was worth letting me look after him a little, so he didn't need me to look after him a lot.