Happiness is often presented as being very dull but, he thought, lying awake, that is because dull people are sometimes very happy and intelligent people can and do go around making themselves and everyone else miserable. He had never found happiness dull. It always seemed more exciting than any other thing and capable of as great intensity as sorrow to those people who were capable of having it.

To laugh often and much ... this is to have succeeded. Probably not from Emerson: here's the full quotation and the story.

The consuming desire of most human beings is deliberately to plant their whole life in the hands of some other person. I would describe this method of searching for happiness as immature. Development of character consists solely in moving toward self-sufficiency.

The more difficult the victory, the greater the happiness in winning.

I don't feel right unless I have a sport to play or at least a way to work up a sweat.

Storybook happiness involves every form of pleasant thumb-twiddling; true happiness involves the full use of one's powers and talents.