" Being needed is incredibly satisfying, and helping others can be deeply fulfilling. Focusing on our own goals to the exclusion of others, especially the causes and the people we value the most, can feel downright selfish and self-centered. But it doesn’t have to. Master marketer Seth Godin says, “You can say no with respect, you can say no promptly, and you can say no with a lead to someone who might say yes. But just saying yes because you can’t bear the short-term pain of saying no is not going to help you do the work.” Godin gets it. You can keep your yes and say no in a way that works for you and for others. "

― Gary Keller , The One Thing: The Surprisingly Simple Truth Behind Extraordinary Results