The 'That Really Rustled My Jimmies' meme features the calm, smiling face of the gorilla mascot from the Gorilla Munch cereal box, used to convey a sense of mild to moderate agitation or being 'unsettled.' Emerging from 4chan's imageboards in the early 2010s, the phrase quickly became a staple of internet slang for when someone is bothered or triggered by a situation. While the gorilla appears serene, the text ironically suggests internal turmoil. The meme's longevity is rooted in its versatility as a reaction image, often appearing in forum threads or social media comments to signal that a specific topic or opinion has successfully gotten under the user's skin.