Similarly, we reach the end of the first section of this book and push off into a dangerous and unknown future. The science of irrationality has proven that people make a variety of errors. Furthermore, markets do not always iron out those errors and people sometimes stampede into and out of markets at precisely the wrong time. Markets can indeed be mean, but because markets can be crazy, opportunities exist for profitable investments.

While markets are irrational, the profits are hard to obtain precisely because $100 bills persist in the lizard brains financial blind spots. Just as we must use a mirror and other tricks to see into the blind spots on our cars, we need help to spot market opportunity. We have one tool so far and that is sentiment. We know that in order to make money, we must make the unpopular moves and attempt to constrain the lizard brain.