Now, the nicest news. You're allowed to be human, Lally's study found. You can make an exception and sleep in. You can ditch your new routine and grab a margarita with your former roommate who's in town for the night. In other words, you can lapse here and there—and still succeed in forming the habit (without going back to Day 1). Self-compassion is key here. (Forgiving yourself actually makes it more likely you'll reach a goal, found a study at Carleton University, while self-punishment resulted in further setbacks.) Simply pick up where you left off the day before—and continue on your path to a habitual happily ever after.