Often we see inexplicable and “weird” changes in painful conditions, good and bad, and often in response to an attempt at treatment — and yet at the same time it’s incredibly rare to find good evidence that any particular treatment works better than placebo. What could account for this? Using a wide paintbrush: it may be that input changes output, that nearly anything that happens to the body has the potential to affect how the body works. Tissue state is just chemistry, and the chemistry of everything is constantly micromanaged and hyper-regulated. Dysregulation and uncomfortable trade-offs and compromises in these processes are routine, but it’s still full speed ahead, all the time, damn the torpedoes, a chemical balancing act that doesn’t quit until we die. Any input may change the equation — the problem is that it’s incredibly difficult and maybe even impossible in principle to predict what inputs will help, or make any difference at all.