The sound comes from The Simpsons, the long-running animated series that began in 1989, where Homer Simpson, voiced by Dan Castellaneta, regularly hums mmmm when he thinks about donuts, pork chops and other food. It became one of his most repeated vocal habits across hundreds of episodes rather than a single famous line. Short clips of the hum later circulated on soundboards and in meme edits, where its meaning needs no context. Its lasting use comes from how clearly it signals desire in under a second.