A new phrase originated from the role-playing game "Elder Scrolls Skyrim." Sometimes a guard in Skyrim will explain his life-story to you and then end it with the fact he took an arrow to the knee thus ending his adventure capabilities. The phrase has become extremely popular on the web, and his used very often.
P.S. REALLY ANNOYING WHEN USED TO MUCH
"I used to be an adventurer like you, then I took an arrow to the knee"