Our cat was miserable after we had kids, just because she used to be the center of attention (and she LOVES attention!). She was a little scared of our son though, so she hid a lot (except at night, when she would sleep next to us).
But then one visit out to California, we boarded her with a local catsitter and she came back to our home with her "factory settings" reset! Now she's out and about a lot more, and so she gets a lot more TLC. She loves it and is much happier! Probably a 6 or 7 now.. whereas before, she was a 10.