The author believes that to be happy in life. It is necessary to get comfortable with the certainty. We all have green lights in life that tell us to advance or proceed. These Greenlights PDFs come in the form of gifts and are kind of moments that give us what we want. But sometimes these Greenlight turn into red or yellow when we are in a hurdle or stress, but over time, these lights can turn into Greenlights as well. But whenever we are passing through red or yellow lights it teaches a lot of new lessons.