Quite possibly on the first day of my senior year of high school, I heard a phrase I'd hear many more times:  "I'm not doing that / going there / staying here / listening to this.  I'm graduating!"  This became known as the "Who cares, I'm graduating" excuse.  It can be conveniently applied to pretty much any situation, as long as the user is graduating from something in the somewhat near future.  It was used for skipping class ("I'm not going to class.  Who cares, I'm graduating."), slacking off ("I'm not doing that homework.  Who cares, I'm graduating."), and eating cookies for lunch ("I'm totally eating 7 cookies for lunch.  Who cares, I'm graduating."). 

It was actually a really stupid excuse because it often had very little to do with the situation at hand.  Plus, most users of the phrase were planning on attending college the following year, so many of the responsibilities they were trying to avoid were actually unavoidable and even detrimental.  "I'm not filling out these stupid applications.  Who cares, I'm graduating.  Oh wait..." 

This is also known as senior-itis, and it popped up again during my senior year of college.  The usage wasn't quite as widespread, presumably because people are more mature in college (ha!), and also because the next phase of life wasn't as attractive as college was to a high school student.  "I'm not taking this stupid final.  Who cares, I'm graduating.  But I could always stick around for another degree."

It turns out this excuse pops up yet again later in life in the workplace.  It seems to happen near holidays or before long vacations.  Instead of finishing a project or doing any type of meaningful work, you think, "Who cares, I'm gradua-- not gonna be here next week."  Depending on your level of importance, it can be very effective.  Honestly, what can your employer really do?  Call you while you're on vacation?  They could, but they might get a return call while they're on vacation.  It's a lose-lose, which is why I'm writing this very thing at this very time.