@foone thinking about the time i was playing Far Cry 2, had to alt-tab to take care of some things, and got distracted enough during it that I decided "nah I wanna go play some games" and launched Far Cry 2. It wasn't until I had finished the session and started shutting down for the night that I noticed the first instance was still running while I was playing a second one.
Sure it isn't two weeks. But still.