Fatigue makes fools of us all. It robs you of your skills and your judgment, and it blinds you to creative solutions. It's the best-conditioned athlete, not the most talented, who generally wins when the going gets tough.
These results add up to perhaps the most important investment lesson of all that can be drawn from this week's market anniversaries: Predicting turns in the market is incredibly difficult to do consistently well. That means that, if your investment strategy going forward is dependent on your anticipating major market turning points, your chances of success are extremely low.