Investing time, money, and energy into your talents, passions, and interests isn't selfish. The world needs that from you. The rest of the world benefits when you hone your skills and talents. When you offer something to the world that's yours alone, it's a gift. Even if we have to pay for it. When you better yourself through education, career changes, etc you tend to produce better 'things' for others. That's hardly selfish. Read Seth Godin's blog and newsletters.