Mistaken identity?

When I went to the bowling alley Sunday night I saw one of the guys talking on his cell phone behind the counter. I wanted to greet him without interrupting his conversation so as I walked by I knocked his baseball cap over his eyes. He glanced up at me with an odd look and then continued his conversation. I turned to greet another friend who was grinning from ear to ear and about to break out in serious laughter. He looked at me and said, "You know that isn't David right?" Sure enough David was also cracking a big smile. They had watched the whole scene with sheer delight. I have no idea what his twin brother thinks of me now...