This sound comes from Shrek, the 2001 animated film featuring Mike Myers as Shrek. The onions speech became one of the movie's most quoted moments because it turns a strange comparison into an instantly recognizable joke. Over time, the line spread through meme culture, reaction videos, and short-form edits as a shorthand for having emotional or personal layers. It still gets reused because even people who have not seen the full movie usually recognize the setup and know the joke is about depth, complexity, or oversharing.