I've steadily come to the conclusion that you can help yourself, you can help others, you can help both in any mix you choose, but the more you help others the less you can generally help yourself. I have always actively sought to help others and usually stretch myself too thin to do much on my own account. But I've only recently recognized that this tendency has cost me position compared to some of my more selfish peers. I do not intend to change my behavior - I can't suddenly become a selfish prick even if I wanted to. But I'm growing an appreciation for just how much self-preservation and self-determination is necessary to excel at competitive careers. If your weekend is spent helping your friends move, it isn't spent finishing that screenplay.