The classic episode introduced the world to the anti-Christmas holiday, “Festivus." After the episode aired, Festivus became more widely celebrated, with many honoring it on Dec. 23.

Carol Leifer said she got the idea for Elaine to wear the waist accessory, with unexpected consequences, from her own experiences.

Elaine Benes was this close to donning a fanny pack.

Seinfeld writer Carol Leifer revealed Tuesday in a Reddit Q&A that she once pitched an idea for a show in which Elaine (Julia Louis-Dreyfus) wears the endlessly mocked waist accessory, with unexpected consequences.

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"[A]t the time, fanny packs were really popular, and I remember wearing my fanny pack under a T-shirt one day, and wherever I went people were exceedingly nice, letting me go in front of them in line, letting me go first wherever I was, and then I realized at the end of the day my giant fanny pack under my T-shirt made me look pregnant!" Leifer wrote.

She pointed out that most of the ideas she pitched were inspired by real-life events.

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"I always thought it would be a great Elaine story if she started to use that, the fanny pack, as a way to make her day in New York a lot less taxing, you know — getting the first taxi because she looked pregnant, getting concert tickets first because people saw her standing in line, and I think they always liked the notion of it but it never became an episode," Leifer continued. "So I love those ideas about Seinfeld because nobody has fanny packs anymore, so it really was specific to the time (except dweebs who wear fanny packs)."

Leifer was a writer and/or story editor on Seinfeld for some 40 episodes in the mid-'90s. More recently, she's written episodes of Lifetime's Devious Maids and ABC's Modern Family.