Aside from playing and purring, they have learned that reading increases knowledge and so they're trying to make up for the lost time. Maybe they'll be even smarter than monkeys or even us. Who knows, maybe you'll even be more surprised when they started talking to you in human language. That's the time that cats will coexists with humans as equals, and not as pets.
One day, when they were playing, they discovered that some kind of sound was coming from a long cord. Whey they put the ear buds in their ears, eventually they were hooked. Now even they have their own ipods and listen to their tunes every now and then. The best part is that they are now singing along to their fave artists and songs.