#30: Bad Jokes
We’ve all done it now and then: you’re standing in line at the gate, and the line is forty minutes long. You have loads of time to stand there and think, which means you have too much time to come up with what you think is a funny joke. And when you get to the front of the line, you tell it.

Do not do this. Even if it’s a joke—even if you think it’s patently obvious that it’s a joke—the airline people don’t know that, and they have to treat it as a credible threat. You’re just going to get pulled aside and questioned, and then you’re going to make your flight late and your vacation is going to start on the wrong foot. Just resist the urge to make a dumb joke.