Long story short: I've worked for the same company for a while now, but I've been in a different unit these past two years. Before that, I was required to churn out this annual report for the unit I was in. It was a major bitch to do - I was happy to leave it behind... Or so I thought. These people, my former coworkers, won't leave me the hell alone! "We don't know how to do the report! Only you can do it!"
Screw that! I helped them out last year on my own time AND dime, mainly because I was hoping to come back over there at a hefty pay increase.
It was extremely satisfying to tell them to fuck off!