The 21/90 Rule: Truth or Myth in Habit Building?
We’ve all heard catchy sayings about building habits. Among the most popular is the so-called 21/90 Rule, which claims: “It takes 21 days to build a habit, and 90 days to make it a permanent lifestyle change.” It sounds simple and inspiring—a neat formula to guide anyone trying to exercise regularly, eat healthier, meditate, or…