1 Chronicles 16:34, GOD's kindness to man is His Mercy that endures forever. Mercy is receiving something we don't deserve.
Proverbs 3:3, "Don't let kindness and truth forsake you. Bind them around your neck. Write them on the tablet of your heart."
I think the saying should be, Kindness begins at home. It is a learned behavior. Those who have been fortunate to have had parents teach this to them through example understand the joy of the LORD. Others have learned of it by people being kind to them in a time of great need. The greatest kindness there ever was or could be was when GOD became a man in Jesus Christ and took our sin upon Him so that we can be with our Almighty Creator forever! Accept His mercy of His kindness of salvation and you too will experience a kindness in your heart that goes beyond anything in this world!