This quote comes from Team Fortress 2, Valve’s 2007 class-based shooter, and is associated with the Engineer reacting to a Spy placing a sapper on his sentry gun. The line became a long-running gaming meme through YouTube, machinima, source animations and remix culture. It stayed popular because TF2 voice lines are highly distinctive and easy to recognize, and this one perfectly captures the feeling of seeing your hard work instantly sabotaged. It still appears in gaming compilations and ironic meme edits years later.