Why do cats move their paws so much when you're petting them?
-- Lisa T., the net
It's called kneading, Lisa. Your pampered Fluffy is drifting back to her kittenhood, when kneading helped stimulate Mom's milk glands while Fluff was nursing. Mom cat spends a lot of time licking her kids, so your petting is probably what makes her so nostalgic. Awwwww.