Our moral obligation to pursue happiness and be happy!

I've never thought about happiness this way, but I think Dennis Prager makes some excellent points. After coming through my Post-Partum-Depression I can unequivocally testify that a happy mother is a better mother. And I'm so much happier now than I was a year ago. My children and husband are happier, too. Do we have a moral obligation to be happy? Watch this and let me know what you think?