The line comes from Dragon Ball Z, where Vegeta uses a scouter to measure Goku's power level during their early confrontation on Earth and is stunned to find it rising past 9000. The English phrase became one of the internet's first major anime memes in the mid-2000s through remixes, parodies, and reaction videos, and the Spanish dub version spread in the same way among Latin American viewers. It endures because the number became shorthand for anything absurdly powerful, unexpected, or off the charts.