Yes, I do believe in this idea. This is because until and unless there is a self-serving idea working the action cannot be done for a long time. The self-serving idea can be gaining self-satisfaction or a sense of achievement by helping others. But it is okay as long as the output is produced. In the long run, altruistic or selfless behavior is difficult to hold on to and that leads to loss of motivation. On the other hand, egoism is a very good motivator as it challenges you and makes you accountable.