I read this book (this copy!) when I was young and it only fueled my love for cats. I was desperate for a kitten, and the way Cleary brought Socks to life made me want a cat friend more than ever. I finally got my cat when I was an adult - and I have the kid, too! Re-reading this book now made me glad I didn't have a kitten and a baby at the same time. My cat is definitely as playful as Socks and has a very similar personality, so reading about the reasons why litter is scattered over the floor made me laugh.
Though I read this as a kid, it almost seems like a book for any age. The Brickers, who adopt Socks, are a young married couple having their first child, so I think the book could resonate with readers of that age as well. Even as an adult past that stage, I genuinely enjoyed the book for the story it told more than for nostalgia's sake, so I think this is one that could appeal to a broad audience. I feel like it's often overlooked in the scope of Cleary's catalog, though.