The line comes from Team Fortress 2, Valve's class based shooter released in 2007, where the Medic is the German doctor who heals teammates with his Medi Gun. Because Oktoberfest is closely linked to German beer festival culture, fans paired this cheerful delivery with the character for seasonal edits, taunt compilations and community soundboards. It spread through TF2 gameplay videos and meme remixes, and it remains popular because the Medic's voice acting is instantly recognisable to anyone who has played the game for more than a few matches.