what does it mean to be happy?

I have been thinking about the things that make people happy. But the key to being happy is not necessarily in certain things or items that you can get to make you happy. It's about experiences. And those priceless things - memories, spending time with people, life experiences, trips - are the things that bring us true joy.
So I have compiled some of my thoughts on this subject.
First is the optimist versus pessimist thing. Being optimistic does not mean you are happy all the time; it just means you have an idealistic view; you hope things will go well and you believe that you should focus on seeing the best in things. Pessimists assume the worst and are glad when good things happen. So in a way, optimists lose because they can be more disappointed than pessimists. But at the same time, pessimists may fail to see the little things in life that optimists do see. So it's not optimism versus pessimism; it's a balance of both.
Something else I have learned: sometimes, it's worse to regret not doing something than it is to regret doing it, especially when it comes to a once-in-a-lifetime chance. Like when I was in Costa Rica, we were all jumping off this cliff with our clothes on, and while I didn't really want to at first, I knew I'd regret it if I didn't. I knew I probably would never do this again, so why not?
Life's about pushing yourself to go places new, see different things, stretch the parameters of your mind, and basically throw yourself into situations that you feel "out of your element" in. Life's about risks, and doing things you never thought you could do. And happiness comes in the pride you gain from doing different things and engaging in new experiences.
And to put it simply, do what you like to do. There's no point in being an orthodontist if you hate it, even if it does pay well. Find a true passion and follow it. And if your passion does not work out for you, would you rather fail trying or fail having done nothing about it?
And finally, surround yourself with friends and family. People who love you, and people you love. People who will be there to listen to you vent when you are really upset, people who will buy you an ice cream, people you can trust, people who you can have fun with. People you would do anything for in a heartbeat.
Not one thing on that little list was a material item. Not ironically, with such a heavy weight placed on materialism in this society, the futile pursuit of satiation of our endless wants often leaves us feeling depressed. Life is so much deeper than that. You just have to be willing to dig.