The longtime YouTuber and Game Theory creator MatPat announced his retirement suddenly today with a video upload titled "Goodbye Internet," a play on his video intro catchphrase "Hello Internet."

In the video, he lets his fans know that the upcoming Game Theory upload on March 9th is going to be the last one that he himself is hosting, with a new host set to take over going forward.

MatPat's contributions to the online video content space are numerous, with him helping to popularize the Five Nights At Freddy's games among non-gamers who found his numerous lore videos entertaining, creating the catchphrase "That's Just A Theory, A Game Theory."

His catchphrase would go on to be a short form of copypasta, with many people saying it on any video or TikTok in which a theory was given for a video game, especially if it was an indie horror title, which he was known to cover.

@shadow.the.protogen New fnaf sound? #fnaf #gametheory #fyp #abcxyz #abcxyz #fnafmovie #spookymonth ♬ THATS JUST A THEORY – Shadow Toaster

After a decade of doing FNAF based content, MatPat was most recently seen acting in the Five Nights At Freddy's movie last year, working as a diner waiter and being able to give a factoid and say his iconic catchphrase, with fans creating edits of him and hoping to see him in the sequels.

@_gyroedits191 #edit #fnaf #matpatedit #matpat #alightmotion #fnafedit #fnafmovie #fivenightsatfreddys #filmtheory #matpatfnaf #gamethoery ♬ original sound – Jojos is peak🦦🦦

Fans of MatPat were quick to show their appreciation for the beloved content creator and all the work he's done over the past decade, with recap videos of his announcement spreading across social media and fans wishing him well in his future endeavors.

Though many of his fans will miss his unique brand of video game content creation, they are excited to see what his future holds and how he can use his years of experience to create puzzles and games of his own.

@milkinthemicrowaver goodbye Matpat. 🫡 Thank you for inspiring me to do what I do. I’ll continue the Papyrus theory series in your name 🫶 #matpat #gametheory #foodtheory #styletheory #filmtheory #matthewpatrick #fyp #foryou #foryoupage #youtuber #fypage #fypp #fypシ #foru ♬ Join Us for a Bite – Piano Instrumental – DPSM