Schadenfreude is a word stolen from the German language. It's not a nice word: it means to find joy over the misfortunes of others. But we've all experienced it. Those of us who consider ourselves to be nice people can usually frame it via some kind of karma. You see a guy driving 100 miles per hour and jackrabbiting across lanes, and then a few miles up the road, you see he's been pulled over by the highway patrol. "Yeah, you reckless bastard!" you think. "I hope they take away your car and your license, ya jerk!" Sure, there's justice involved... but face it: you're happy because that guy is miserable.
Some people would interpret the opposite of schadenfreude as feeling sorrow for people's bad fortune (aka sympathy or empathy), or perhaps feeling good for others' good fortune. But I disagree; really, the opposite of schadenfreude is another, less well known German word: Gluckschmerz. This rather nasty-sounding word has an equally repugnant meaning: feeling displeasure when good things happen to others. It's kind of like spite, but worse. it's also similar to envy, but the difference is that you may not even want whatever has made the other person happy; you just aren't happy because you know they are. It's not an emotion to be proud of in any case.
I don't advocate suppressing emotions, positive or negative. And yet, being filled with either schadenfreude or gluckschmerz is sure to put a taint of corrosion on your soul. The former is just plain mean; the latter will leave you bitter. I try and think of myself as being a pretty enlightened person, with a lot of compassion, but I'm not immune to either of these feelings. Especially when it's a situation involving another person with whom you've had a checkered history, it's difficult to not allow these dark feelings to affect you.
Happiness is a hard thing to define, and God knows there have been enough attempts to create a dictionary entry for happiness that applies to all people. I can tell you one thing: a sure-fire way to avoid happiness is to spend your life comparing yourself to other people, or to be overly concerned with the actions of other people that don't affect you directly. I have spent little time in my life doing either, especially in the last ten years or so. I guess I got to a point where I realized that life was way too short to waste a moment of it being consumed by negativity of any sort. Still, every once in awhile, they rear their heads, and I walk around scowling for no good reason. Fortunately, when it happens to me, it's pretty rare and it doesn't last long.
In fact, I'm over it already. Back to the happy.