This document defines a meme as an idea that spreads rapidly through written text, images, or other cultural information. It analyzes the video clip "Fat kid on a rollercoaster" as an example meme due to the large number of remix videos it has spawned and its widespread popularity online, with over 3.9 million views on the original video and 179,000 image search results. The document notes that the clip has been frequently imitated on YouTube and discussed on Twitter, demonstrating its status as a viral meme.