Why happiness?

      Whenever people discuss success or quality of life the measure that almost always comes up is happiness. Because we know that money and power are pointless status symbols compared to happiness. We know that happiness is a good feeling, which is why we chase after it, right? But really, is happiness a useful measure of anything? Furthermore, should we even bother to try to be happy?
      Happiness is, like all emotions, a collection of chemical and electrical impulses in the brain. The origins of happiness are likely a learning tool, the brain giving itself positive reinforcement for behaviour that continues one's genetic material. This is most obvious in things like the orgasm. Species that found sex a reinforced behaviour were more likely to do more of it. So useful started to give happiness, in much the same way dangerous and harmful things started to give pain. In a way emotions can be seen as a shopping list: we know what we want and what we don't want, but as we have grown in intelligence it has become more effective for us to work out our own way of getting the shopping/positive events, instead of having a predefined way of achieving these events. So emotions give us the framework for innovation. That metaphor might seem a little mish-mashed, but it kind of makes sense.
      So that's why emotions and in particular happiness exist, but do they belong in a modern world, at least in their current form? Human's prize themselves on being rational, despite this not really being true. An action can be rational in getting a certain outcome, but if the desired outcome isn't rational then the action is not a truly rational one. So while humans are capable of making rational decisions in regards to achieving positive emotions, if those emotions are merely bi-products of evolution then in what way are they rational? Right now happiness is merely a measure of how well you can achieve primal goals in a modern world. Believe it or not, right now money can buy the things to satisfy most of those primal goals and, in turn, happiness. Everything in our society is still geared towards getting the right emotions, just like the first apes to walk upright. By using happiness as a measure of success we are highlighting how little we have moved on as a species.
      To finish I'd like to ask a question: If you could rewire the human brain to award happiness for different actions and events, how would you change it to better equip us for a modern world?