Are you a 10? Typically when we hear this type of question, we think that the person is asking us if we are good looking. In Japanese culture, the number 10 or juu is a homophone for juubun (十分) which is intended to mean, "Replete." Thus, the number 10 is lucky because the number 10 means to be content. In the west, we pursue things in order to achieve or acquire happiness and thus happiness is a result of taking - I receive and thus I am happy. In Japan, contentment is often associated with living a life of purpose or meaning and happiness comes as a result of giving.
The number 10 then reminds us that true happiness is a result of finding inner contentment instead of outer attainment. Finding contentment is a result of having a living a life of meaning. To have meaning means that we "get to" share or give something with the world and with that we are grateful for the opportunity. When we have meaning, then contentment, and thus gratefulness then true happiness is not far behind. True happiness is then a function of giving from a place of contentment and not taking from a place of fear.
Are you a 10?