Emotional intelligence is the skill to be aware of, control and ultimately express emotions. The latest studies suggest that EQ (emotional intelligence quotient) is more important than IQ (intelligence quotient) for succeeding in work, life and having a better health in general. By mastering it, you could be aware not only of your own emotions (and therefore drivers), but also of the emotions of the people around you (and therefore guide them and in general benefit from the extra information).
Self-awareness is the first step (out of four) in improving your emotional intelligence. This skill allows you to spot your emotions as they arise (and not after their devastating effect). It also helps you to anticipate the upcoming emotional reaction by defining and being aware of the things that drive you towards those emotions.