Hi Richard,
Someone said, "Happiness is like a half cup of tasteful wine. Pessimistic (悲觀) people complain not having a full cup while optimistic (樂觀) people find themselves lucky to have a chance to taste it."
Richard, we need to be thankful for what we could still have, e.g. a good health, a good family, a good education, a good friend, etc. Happiness is not equal to how much you get but how much you recognize.
With love, Patrick