Of course, people who break up for this reason don't always spend the rest of their lives apart. The rest of the quote that Pitt cited allegedly goes like this: "If you love somebody, let them go, for if they return, they were always yours. If they don't, they never were." There's always a possibility that someone can change or come back to you, and Derhally says it does happen. "If you hit a wall in your relationship, that's one thing you could do to break a cycle," she says. For example, if you're in a relationship with someone who's not very committed, but you're really committed, waiting around for a person to make a decision isn't very healthy, she says. One person has all the power in this scenario, so they would have "no incentive to change things, because they can do whatever they want," she says.