The line comes from Back to the Future, released in 1985 and directed by Robert Zemeckis. In the film, Dr Emmett Brown, played by Christopher Lloyd, explains that the DeLorean time machine needs 1.21 gigawatts of electricity, which he pronounces as jigawatts. The mispronunciation was kept from Lloyd's delivery and became one of the movie's most quoted moments. Clips and remixes spread the shout across forums, videos and soundboards, where it survives as shorthand for needing an absurd amount of power for anything.