The line comes from Team Fortress 2, Valve's class based shooter released in 2007, where the Scout is the fast talking Boston runner known for taunts and overconfidence. Fans clipped his panicked voice lines for forums, machinima, and later short form gaming edits, turning a quick in game reaction into a reusable punchline. It stayed popular because TF2 voice acting is instantly recognizable and the emotion is universal, so creators can drop it into any game or real life clip where someone realizes too late that they are completely exposed.