Emotions are our master and we are humble servants to them. All things that we do can be explained through our endeavor to reach a certain emotion or to avoid another. Emotion is that very mechanism that makes the human species to work in such way as it appears.
What is emotion? An emotion is developed and refined stage of instinct. Instincts make a spider to weave a web, to prey insects for food and to mate. Do mammals and birds live by their instincts or by their emotions, that I do not know. I've only heard that only rabbits and humans take pleasure from sex. In any case, at least human species has developed a more complex motivator: emotion.
Thus humans do and aspire to things, because they believe they are going to reach some emotion. This happens either consciously or subconsciously. People, who lust for money, do so, because they believe they will achieve perhaps a sensation of greatness and a sense of safety, possibly even such that'd be permanent. People, who don't hunger for riches might already recognize in themselves that money just doesn't produce a more positive result in person's emotions.
This all means, that we don't yearn things, we only yearn the emotions that we believe are behind the things we desire. This is either conscious or unconscious. We are different as persons. To others, money and power really does bring great feelings. To others, life is just a struggle against negative emotions and therefore they choose to live riskfree life and make sure they pay their mortgage so they don't have to experience guilt or distress and are not too outspoken, so that they wouldn't have face challenge and through loosing, shame.
This means that there are no emotional and no rational people. There are just people who get the high or the pain from different things, or at least they think they do. In pursuit of happiness, those are in the strongest position, who know their own emotions. That is: what things bring positive emotions and what things negative.