You know how little things can create major pain? In December, I broke my middle finger playing hockey. On the scale of illness and injury, mallet finger is a trivial annoyance. It hardly merits discussion. It’s a scratch, a nit, a bother. But my seemingly inconsequential finger break has caused the rest of my hand, body and mind to develop a whole list of ailments, throwing me for a loop. Such is the effect of a simple change on a complex system. As in English folklore, it was the want of nail that lost the kingdom. Because my middle finger doesn’t bend as it did, I can’t make a fist. I drop everything that I pick up. I’ve become a nine fingered typist and a one handed slouch. Because I couldn’t hold a racquet or a stick, I stopped competing in sports. I’ve gained a little weight, again, which I’ve now resolved to lose, again. And the dog is annoyed that I don’t throw the tennis ball and I’m annoyed at the dog. You get the picture. When we have to confront the unfamiliar, we are thrown out of rhythm. We may become depleted of energy, which can lead to poor decision making. We can all find examples in our own lives of bad decisions made while tired, impaired or in pain. How we think and act in times of stress, tiredness, grief or pain may be very different than when we are well, happy, rested and calm. There are important investment and economic implications of this insight. Financial advisors counsel us not to make life-altering decisions when confronted with sudden, stunning loss; for example, after the death of a spouse or loved one. It is easy to make a bad call, and even easier to let someone we trust take control over decisions.