The phrase you don't wanna know has circulated online as a stock reaction line rather than a quote tied to one confirmed scene, which is why it appears on soundboards without a clear credited source. Its humour comes from implication: the speaker suggests something too awkward, gross or chaotic to describe, and the audience imagines the rest. Short reaction clips like this spread through meme edits, group chats and short-form videos because they can be dropped onto almost any setup and instantly change the tone from curious to cautiously amused.