Well, barring time travel, of course. . .

There are no “takebacks” when you communicate.

Whether it’s Interpersonal or Mass Communication, once a message is sent out, you can’t edit it.

Two people are having a conversation. One says, “I don’t love you anymore.” That person cannot retract that statement without negatively impacting future messages that they may want to send. The person who was told, “I don’t love you anymore.” cannot simply forget that the statement was ever uttered. It’s impossible. Human beings don’t work this way.

A person makes a movie for mass consumption. People watch it. He has communicated a story to a mass audience. In it, there is a scene where one person shoots another. The person that made the movie cannot alter this scene without negatively impacting those that have already watched the movie.

In short, Han Solo shoots first. Han Solo is a murderer. I don’t care what George Lucas does. Besides, Greedo shooting first is ridiculous. I don’t care how dark the cantina is, he probably wouldn’t have missed from 3 feet away.