If you punch “self-help” into Amazon, you’ll get something like 294,000 results. We are a people profoundly concerned with improving our weight or athletic performance or sex lives, always looking for easy fixes, for effortless ways to change our most ingrained habits. Much of what is offered is pseudoscientific at best, of course, but that hasn’t stopped an ever-growing army of charlatans from extracting millions from those of us who are desperate to improve ourselves.