Cats never wonder why people bring them food. They never wonder if they deserve to be massaged and tucked away into warm arms, or why there is a lap to sit on, and fine blankets and pillows when the lap is not there.
Cats have a deep and centered sense of deserving all of these things. "Of course I should be loved."
I think it's one of the things I like most about cats. And when I feel depressed I try to emulate them.