Happiness is a peak. It is derived from the word "happen". It can not be a constant state. More important is comfortable. Problems are a normal part of life and that fact is not related to comfort or happiness.
I am comfortable with no problems I can not handle and I have many happy moments and much enjoyment of life. There in very little in my life that I have the power to change that I would want to change. My life is very acceptable.
I have no unanswered answerable questions and I have no fear of gods or ghosts and I certainly have no fear of impending doom. Death will certainly come someday. I hope that day finds me in a warm comfortable bed in as little pain as possible.