Happiness is a fairly broad category of mental states, which encompasses contentment. Happiness is linked to both a set of internal subjective feelings (impossible to describe, as there's no reference point. See also: the color red), and to a particular set of external behaviours which are consistent across the majority of humans (smiling, laughing, etc). If I wanted to communicate the internal subjective experience of happiness, I'd do it the same way I would the subjective experience of a color- I'd wait until I saw you experiencing it, and then I'd say "That feeling, right there. That's happiness." This is easier with colors, because I could just point to one, but it works with emotions too.

Much like yourself, I tend to think of happiness as a barometer of sorts. If I'm unhappy, it means that something's wrong which needs fixing. It's not hard to see how this perspective can be reversed, though. To say that I seek to be happy and I do so by finding/building a satisfactory environment, or to say that I seek a satisfactory environment and I gauge this via happiness- in practical terms these perspectives are indistinguishable.

kala ta pes dike mou.

Content, to me, is a neutral term. A lack of wants or needs plaguing me.

Happiness occurs when I am moved beyond that, by something which touches me positively. Playing a computer game, talking with friends, chasing my nephew around the garden, laughing at some silly thing with my wife. All of these are actively positive, beyond simple contentedness.

To me, 'being happy' is a vague, categorical, unfocused term like 'good', 'positive', 'introvert', or 'extrovert'. You can go into specific behaviors and feelings and then it makes a lot more sense.

For example, the author could be 'happy' in most areas of his life, but the choices he made in his life could make his dating life harder (if he's single) and he finds he's less 'happy' in that area.

In psychology, the terms hedonia and eudaimonia are somewhat broadly used to characterize two common modes of well-being. That might lead you to useful reading.

According to the hedonistic view: "Happiness, understood as enjoyment is indeed a good candidate for an intrinsic value. ... It's worth pursuing for its own sake, it's valuable in its own right."

But happiness doesn't equal good life, there'are many different approaches to achieving it. I think "The fundamentals of Ethics" by R. Shafer Landau summarizes best the most important ethical theories.

It's like being in love: you can't describe it, but you'll know it when you feel it.

You might be like me and not be particularly good at introspection: http://en.wikipedia.org/wiki/Theory_of_multiple_intelligence...

It took me a long time to be able to recognize things like happiness and love.

Happiness is when your cheeks hurt from smiling too much. Happiness is riding a jet ski. Happiness is enjoying a beer with your friends. Happiness is accomplishing something difficult. Happiness is looking forward to whatever you're doing today.

To me, that's happiness.

Happiness is some state of brain chemistry that humans find desirable and, having experienced it once, attempt to achieve that state again.

Contrast this to pain, which most people attempt to avoid experiencing again.

i get happy when things "connect" in my head. It's a rush.