The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!! The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!! The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!! The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!! The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!! The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!! The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!! The 21-day effect!! It takes at least 21 days for a new habit to develop, commonly known as the 21 effect!!