Not being one who excels in debates, this is the way I read the happiness statement.
If you spend your life discontent, always wanting, life will pass you by. When you are old and gray, you will realize that you missed the joy of your family, your children, your grandchildren and your friends because you spent your life wanting more instead of living life to the fullest.
I do not disagree with any of your comments just the interpretation of the statement.
I feel sure we are all in basic agreement.
Happiness is a way of living, not a result of anything else.
No we are in complete agreement, all 3 of us.