Habit protocol

Research (Lally, 2009): automaticity takes 18–254 days, median ~66. Not '21 days'. Missing one day doesn't derail — what matters is not missing twice in a row. Phases: days 1–20 — high motivation cost (do the minimum), 21–45 — formation, 46–66 — automation, 66+ — maintenance. Rule: shrink the habit to impossible-to-fail ('1 push-up').