You’ve heard of the Quantified Self movement? It’s the rise of watches, clips and bracelets that monitor your physical activity, sleep and other biological functions. The idea is that continual numerical awareness of your lifestyle works to motivate you: to park farther away, to get off the subway one stop sooner, to take more stairs. You study the graphs, you crunch the numbers, you live a longer, healthier life. (And you try to avoid being a crashing bore at parties.