The 1995 movie, Apollo 13, is one of my favorite thrillers. It involves space, a real story, and multiple engineering problems. Between many memorable scenes, there's one in particular that can teach us a lot about programming. While the team of astronauts is preparing a complex procedure, the commander, played by Tom Hanks notices, that his colleague placed a sticker on one of the command switches saying Don't flip this. The commander asks his colleague why he did that, and his answer is something along the lines of My head wasn't clear, and I was afraid I would flip this and send you to space. So, I wrote this to remind myself not to make this mistake.
If this technique works for astronauts, it should work for programmers. Fortunately, we have the compiler to tell us when we do something wrong. However, we need to tell the compiler...
