Happiness is a feeling. Feelings are subjective because no one can tell you how to feel about anything. You can have two people in identical situations but still feel very different ways. And that's okay. But there is no graph, flowchart, or anything definable that can make a realistic determination on one's happiness. Because again, it is a feeling. You as an individual have to develop your own definition of happiness and determine whether or not you are happy with the way things are.
DaGoobergoobs t1_jegdb2u wrote
It can't. Happiness is subjective.