One afternoon in the mid-1980s I was sitting in a park on a blanket beside my dog when a Frisbee rolled up and hit me in the back. I turned around and spotted two guys standing a short distance away with hopeful looks. After standing to return their Frisbee, I moved to sit back down, when, to my surprise, the two strangers threw the disk back to me—an invitation. We formed a triangle on the grass, beginning a spontaneous game of three-way toss. But minutes later, for no discernible reason, they stopped throwing the Frisbee to me. At first, it was sort of funny, but when it became clear that they were not going to include me again, I felt foolish, awkward and hurt. I felt ostracized.