To forget oneself is to be happy.
happiness
There is no duty we so much underrate as the duty of being happy. By being happy we sow anonymous benefits upon the world.
benefits duty happiness
The habit of being happy enables one to be freed, or largely freed, from the domination of outside conditions
In his own life, then, a man is not to expect happiness, only to profit by it gladly when it shall arise; he is on duty here; he knows not how or why, and does not need to know; he knows not for what hire, and must not ask. Somehow or other, though he does not know what goodness is, he must try to be good; somehow or other, though he cannot tell what will do it, he must try to give happiness to others.
christianity happiness
Happiness and goodness, according to canting moralists, stand in the relation of effect and cause. There was never anything less proved or less probable: our happiness is never in our own hands; we inherit our constitution; we stand buffet among friends and enemies; we may be so built as to feel a sneer or an aspersion with unusual keenness and so circumstanced as to be unusually exposed to them; we may have nerves very sensitive to pain, and be afflicted with a disease very painful. Virtue will not help us, and it is not meant to help us.
goodness happiness suffering virtue