Happiness is a state of mind in which our thinking is pleasant, at least for a good portion of time. Note that it is a state of mind, NOT a set of happenings.
"Happiness is when what you think, what you say, and what you do are in harmony."
It is easy enough to be pleasant;
When life flows like a sweet song.
But the man worthwhile,
Is the one who can smile,
When things go dead wrong.
(not mine, I just can't remember where I know this from)
What is happiness to you? What do you need to experience true happiness?