NPR reporter David Kestenbaum tells host Ira Glass about the time, when he was doing graduate work in physics, he and his other single friends decided to figure out the mathematical probability that they'd find girlfriends. They wanted to know what the chances were that there was more than one person in the world for them. And This American Life Producer Alex Blumberg and his wife, Nazanin Rafsanjani, reveal the subject of their first fight: They were in love, walking in the park, when Nazanin asked him if it felt like fate—like she was the only one for him. (Yes Alex, there is a wrong answer to that question.) When you're in love, it always feels like it was meant to be, whether or not it really, statistically speaking, is. (9 minutes)