The phrase comes from the Latin Spanish dub of The Simpsons, where Bart Simpson uses antes eras chevere to tell someone they have changed for the worse. Clips and screenshots of the scene spread widely on Latin American social media, WhatsApp groups and meme pages, where the line became shorthand for nostalgic disappointment. It is now used far beyond Simpsons fans, posted as a standalone audio or caption whenever a person, brand, series or trend is seen as less cool than it once was.
About this sound
Bart Simpson saying antes eras chevere in the Latin Spanish Simpsons dub, a short disappointed reaction clip used when someone is not cool anymore.
This is Bart Simpson delivering the line antes eras chevere, meaning you used to be cool, in the Latin Spanish dub of The Simpsons. His voice is flat, disappointed and a little hurt, stretched over about two seconds with no music or other effects behind it. It is not an angry shout, it sounds like a kid quietly giving up on someone he admired. That dry delivery is why it lands so well as a reaction, instantly turning a small letdown or a change in behaviour into a funny, nostalgic put down.