My dad once told me the only way to be happy is to either be a great person or a bad person.
If you are a great person, he says, when someone asks you for a favor, you do it gladly. Of course I’ll pick you up from the airport! I’d be happy to water your plants! It makes them happy to make you happy! If you are a bad person and someone asks you for a favor, you decline and never have another thought about it again because you’re a bad person.
