Excerpt: "Sometimes when I see a news story about the stock market that sounds either too ominous or overly optimistic, I ask myself what headline I might write instead. It usually goes something like this: 'In the long run, stock returns are likely to revert to historical averages.' It's not very snappy, sensational, or even very interesting. But it's a guidepost that you can stick to in both good markets and bad ... for the long term."