Eating, drinking and having fun all day is not necessarily happiness. Living in a big house and driving a luxury car are not necessarily happy. But two people may be happy to rent a house to eat instant noodles, provided they are willing. So happiness is not a standard, but a state of mind. Only when you are willing to do something will you feel happy. It doesn't matter if you are tired and earn less. So the happiness of life is nothing more than the word "I do".