The definition of happiness is very broad, and nothing can be defined. Only after personal experience will you know what happiness is. When you do good deeds, when you are loved, when you get good grades in exams, when you do things that others have not done, you will feel happy. There are many such things, which are common in your daily life. If you pay attention to yourself, happiness is everywhere. Happiness is just a feeling, fleeting, and happiness is a state, relatively lasting. I hope you can find it soon, catch it and enjoy it. I wish you happiness ~