I don't necessarily disagree with the other posters, but I'm not sure one can find true happiness within oneself. Satisfaction? Perhaps. be more happy than sad? Why not. But real, meaningful, happiness? I'm not sure.
I come from a philosophical and religious background whose roots are rooted in the genuine happiness that comes from a deep connection with God and in service and dedication to others. I don't believe it qualifies as happiness within itself.
Personally, having spent a great deal of my life without my family, working at being the best I can tell you, I was "happy," but not nearly as powerfully happy. Wasn't as much of a family as I am now. I was content, had a good time with good friends, but looking back I now realize that I didn't know what real happiness was.
I knew at the time that I was working to help others, usually through non-secular service clubs or church groups—and that was great, even satisfying. A better time was when I was alone at home playing computer games, and I love playing computer games. Helping others still, counter-intuitively, was better for me then just focusing on myself and doing things only for me.
Now that I have my own family, my life is much more perfect. Actually, I can't even compare two parts of my life like this. It's like I've had a slow metamorphosis that I didn't even realize I was experiencing until I was on the other side of it. Now that I think about it, I'm probably still going through that change and won't believe in seven more years how much my life and my existence have changed.
I'm not the same person I was, and while that person would describe himself as "happy," he really had no idea. And I'm really happy now that, despite getting little sleep, being yelled at almost constantly by three crazy little guys, strangers to my Xbox and gaming computer, I need to go back to my many writing projects. , disappearing studio backlots, no longer going on weekend bike rides, no longer watching every blockbuster movie on opening weekend, and countless other things that used to bring me joy. I now have things - people - that matter to me more than the air in my lungs, and I have a deep and abiding faith in God, and when you add to the person I was before, a person is satisfied and with Him. Instinctively own your own skin, and you have the earning of real, meaningful happiness.