The phrase comes from French internet humour, where Bigflo's name and voice are attached to a short roast about a forehead being 15 kilometres long. The line 'alors écoute-moi bien' works as a familiar attention-grabbing opening, so the clip spread as a reusable sound for French-language meme edits, reaction videos and short-form posts. Its appeal is simple: listeners recognise the setup immediately, even without seeing the original video, and the exaggerated measurement makes the joke easy to reuse for friends, photos and playful insults.