There’s been more than a little buzz about habits lately. To take just one example: James Clear’s 2018 book “Atomic Habits” spent an eye-popping 260 weeks on the New York Times bestseller list. Books like these – including the 1989 classic “The 7 Habits of Highly Effective People” – promise that habits are a key to transforming your personal and professional life. And they draw on our collective, perennial desire to form good habits (and break bad ones) as a way of optimizing our life. But...