This phrase is good to keep in mind with relationships as well. I'd venture to say a lot of complications can come from your partner taking something you said the wrong way. Now when I'm writing and speaking, I reflect back to that little phrase a lot. I'm working on trying to make something exactly what it's supposed to be.
At the same time, keep in mind that this issue has been used for the basis of romantic comedy for as long as it has existed. Sit down and watch any episode of George Lopez, and you're sure to see him trying to say something nice to his wife while she gets offended because she perceived it quite the opposite of the way he meant.
Have you ever said or wrote something that came off the wrong way?