What is happiness?

I read about the following while I am on vacation with my family in Hong Kong. Happiness is not the absence of problems, it’s the ability to deal with them. If Mihaly Csikszentmihalyi and Matt Killingsworth are right, we should be paying far more attention to how we spend our time than to the stuff we accumulate. They argue that it’s not the activity we choose to do that’s important to our happiness: that turns out to have little to no effect on our state of mind. Instead, it has everything to do with the quality of our mental focus in the moment. I would add to the above that happiness is also about the successful outcome of how to deal with the problems. Life is full of problems. As Bruce Lee put it, life is a process o preparing of death. It is the process that counts, since everyone will die. What do we want people to remember of us after we die? What good do we want to have done to this world after we die? Don't we want to have made some good difference to this world due to our presence? Everyone may have different answers to the above questions, but it is important that we each have some answer instead of no answer at all.