The line comes from Meet the Soldier, Valve's 2007 character short for Team Fortress 2 introducing the Soldier class. In the video he lectures unseen recruits while misapplying military history with total confidence, a running joke built around the character's delusional patriotism. Clips of his speeches were shared widely in early gaming forums and YouTube edits, and this Sun Tzu moment survived as a standalone reaction because it works without context. Players still quote it before attacks, in strategy games, and in meme edits about doomed but determined plans.