Several years ago I made the mistake of forgetting my wedding anniversary, and I promised my wife I'd never forget it again. Since I have such a lousy memory, I instructed my computer to remind me two weeks before our anniversary, and I believe I used the phrase "Don't forget your anniversary, butthead" as the reminder's text to make sure it got my attention.
A few years later I decided to get a new computer, so I gave my wife my old system. Yep, you guessed right - I forgot to remove the reminder. Which meant that one morning her computer greeted her with "don't forget your anniversary, butthead."
Luckily, she eventually figured out that the reminder was meant for me, not her - but I still wonder what went through her head before she came to that conclusion.
PS: My wife forgot our anniversary the following year, so my record is clean now.