I think it is cats mostly don't give a damn. My two will sometimes respond to what I say to them and other times will just look at me like, so what. The one exception is my tom cat who, from the time he was a kitten, would decide to start nipping at me. I would respond with a very firm "Don't bite mom", he would then switch to licking me. He's 8 years old and that is still the routine. And yes, they do love their routine.