As I write this paragraph, my wife and our good friends are wondering why I'm selfishly lagging behind and not meeting them for an afternoon of sitting in the sun. I'll get there soon. And when I do, I'll feel energized and satisfied and be far more fun to be around. No one will think worse of me in the long run for being thirty minutes behind for a full day of fun that they have already started. But everyone will appreciate that I'm in a better mood when I show up. That's the trade-off. Like capitalism, some forms of selfishness are enlightened.