The Matrix arrived in 1999 and became famous for its idea that reality is not what it seems, which is why it still supplies the language for mind blown reactions online. Clips labelled as a reaction to it are shared less as film audio and more as shorthand for disbelief, sitting alongside sudden suspense beats and oh my god, wow moments on soundboards. As short form video grew, creators reused the reaction for twists, conspiracy jokes and impossible coincidences, because the reference is understood instantly even by viewers who have not seen the film recently.