This is so; happiness is episodic and sporadic, it isn't a permanent state of being, nor is it intended to be; it comes and goes for everyone.
I don't doubt if they are happy. I doubt how they achieved that happiness. Did they step on others, or are they looking the other way while others are stepped on?
Martha Steward said one of the biggest things that she liked when she was in prison was not having to worry about all her stuff in 5 different homes. She said it was the first time in a long time that she could not worry that people were stealing from her.