The 'It Defines Who I Am' meme originates from a pivotal scene in the 2004 Disney-Pixar film 'The Incredibles.' In this moment, Bob Parr (Mr. Incredible) is discovered by his son, Dash, while looking at his old superhero suit and memorabilia. When Dash questions why he cares so much about the 'glory days,' Bob solemnly replies, 'It defines who I am.' The internet adopted this dramatic quote to humorously justify obsessive behaviors, niche hobbies, or specific personality traits that others might find strange. It has become a staple template for self-deprecating humor and defending one's hyper-fixations against the judgment of friends and family.