When I was a kid, we had a cat. I spent many evenings with him on my lap while I read books or watched t.v. Sometimes he'd do this little thing where he used his front paws to knead the blanket over my legs and he'd purr loudly while doing it. He really liked it if I gave his head a good hard pet while this was going on. I just saw a video of a cat fucking a blanket and I now realize that's what he was doing. Up until now, I'd always thought he was just doing what cats do to show that they're content.
I am so embarrassed.
Added @ 11:11 p.m.
Here is the video that brought back so many memories.
Thanks for linking this in the comments, Jeni!