Recent research suggests that anything more than a short lapse in a behavior we hope to make habitual (say, multiple missed visits to the gym rather than just one) can be costly. Seinfeld’s mantra “Don’t break the streak” is astute. It also helps explain the logic behind twenty-eight-pill packages of birth control. Scientifically speaking, the pills are necessary only on the first twenty-one days of a twenty-eight-day menstrual cycle. However, most birth control packages include seven sugar pills along with twenty-one hormone pills to ensure that people on birth control won’t fall out of the bit.