That article is one of my favorites. It doesn't make sense to me when people lower their happiness because of bad luck that happens to millions to people every day... There's no point in dwelling on the inevitable.
I'm in a position like Sam988, always happy because I'm doing things that will achive my goals. When you become commited to your goals, it is success that is inevitable.
And if you can enjoy the journey of achieving the goal as well as the result, life is bliss.
Most people think they can't control their feelings and emotions. Ha. I've been able to control my emotions since I was very young. If you want to feel happy then think of something that makes you happy. I make sure as much as my thoughts as possible are positive, so my default state of being is joy. Happiness comes before external results, but both are great to have in life.