Everyone has his or her own measure of successful investing. Most measure their performance over time against some benchmark. The benchmark should be selected to reflect the investor's strategic positioning, but the near-universal fallback is the S&P 500 (SPY). If you're beating SPY, you get bragging rights. So, why not simply invest in SPY as Warren Buffett advises? Well, that's a topic for another day, but I suppose it's another case of a classic tenet of behavior economics: Most of us take up the challenge because we believe ourselves to be smarter than