Laundromat: Someone Calls Out Biff's Name

About a third of the way home, someone called out Biff's name. He didn't recognize the person's voice, but stopped running and turned towards them anyway. When he did, he saw that the person was much older than anyone he knew, other than his parents, his teachers, and the coach. In fact, this person might have been even *older*, like maybe 60 or 70 years old. How did this person know Biff? "There you are," the person said. "What are you doing way out here?"