Even if he fails in life, he or she doesn't blame destiny for it. Also, such a person doesn't lose hope. He is always hopeful and optimistic person will always be happy. Moreover, such a person will be able to find pleasure even in the pain. Also, a happy person doesn't depend on others or external factors to make him happy. He will manage to be happy even in the worst situation. No one can make us happy. We are only responsible for our happiness
It doesn't affect me, you'll be happy however the situation might be. So actually, happiness is not an external thing. It's an internal, it's an emotion or it's your thought process. If you decide to maintain it, you'll surely maintain it irrespective situation. If you decide that others words or others opinions will affect me, you will never be happy