Yesterday I sent a message to a friend that was returning home from conference. I told them to fly safe. After I had sent this I was struck by the redundant nature of this very common saying. Was I imagining that somehow, her actions would ensure the flight was successful? That she somehow could ensure that she flew safe? Unless your friend is a pilot, I imagine the answer to that question is always going to be no. Did I think that she was going to be a bit casual and relaxed about her flying today, but now I had drawn her attention to the fact, she would fly safely all because of me? The truth is, of course, that we say these things to people because we want them to be safe and somewhere in a dark superstitious past we developed a custom of wishing people luck believing it would have an effect. That it doesn't, really does not matter. It makes us feel good when we wish someone who we care about luck, a safe trip, all the best etc. I guess it makes them feel good too.
In the end I suppose that is all that matters.