One summer trip. Two teenagers. Four grandmothers. And a little bit of luck. I don't know what I like, and a vacation might be what I need to find my own interests. For my high school graduation, I'm gifted a senior tour of Ireland. Except, it's the wrong kind of senior. In an unlucky mix-up, I end up on a two-week tour for senior citizens. I may be the rebel on a holiday, but I'm not the only teenager. The bag...