Happiness means a lot of things to a lot of people. When it comes to saying one is happy, I believe that it has to do with having that peace of mind. No matter how much we make on earth, once the peace is not there, I always have the feeling that such persons ain't happy. To be happy is to feel at home with how life is treating us and always believing that tomorrow will be better than today.
Happiness is a feeling, a sense of contentment. In my opinion, other people and things will never make you happy, you can only be happy on your own if you can see the beauty in the world.
The truth of the matter is that happiness is subjective. What makes Mr A happy might not make Mr B happy. So, it's all about knowing what works for you.