aslfjiasf parent
Our cat does this on soft blankets, but unlike the other cats mentioned in the comments, she doesn't look like she's enjoying it. Her ears are back and her brow is furrowed and she looks like she is unsure why she's doing it. Alternatively, she looks like she's hatching an evil plot to take over the world.
Option B. Always option B.
More seriously, I get the impression Being A Cat is rather intense and takes up their entire concentration.
That's what I've always said about kittens; why they run around and get excited - they're under a lot of pressure to be a cat and what's a higher standard then that? Once they're fully a cat they take it easy a lot though because y'know cat.