Every January, gyms sell memberships to people who will stop coming by the second week of February. The pattern is so reliable that fitness chains build their pricing models around it.
Habit tracking has a marketing problem, and the problem is that the marketing is aimed at people who enjoy maintaining systems.
Hotel rooms are hostile to routine. The bed is too soft or too hard, the curtains leak light at 5:40 a.m., and the coffee maker produces a brown liquid that tastes like the memory of coffee.
January 17 is the busiest day of the year for gyms in the Northern Hemisphere, or so the running joke goes, and by the first week of February the elliptical machines are free again.
Somewhere around five in the morning, a kitchen light clicks on and a kettle starts to rattle. Twenty feet away, a phone alarm gets swiped into silence for the third time.
Twenty-one days. That number has been passed around offices and gyms and kitchen tables for decades, usually with the confidence of a law of physics.