When Jerry refers to “Golden Boy” on “Seinfeld,” he means his favorite T-shirt.
Jerry explains the nickname in “The Marine Biologist,” telling Elaine that he has owned the shirt for six years. It is his best shirt and the first one he wears after laundry. Jerry treats the garment as if it were an athlete with a career: each wash brings it closer to death, but removing it from regular use would supposedly break its spirit.
The joke turns an ordinary piece of clothing into a beloved, aging character. Jerry’s sentimental monologue is especially funny because Elaine is busy handling a phone call and has little interest in touching or discussing the shirt. By the end of the episode, Golden Boy does not survive the wash. Jerry replaces it with a blue shirt he calls “Baby Blue.”
A common mix-up is confusing Golden Boy with another famous “Seinfeld” garment, such as the puffy shirt. The puffy shirt is central to a different episode, while Golden Boy is Jerry’s old yellow T-shirt. The reference appears in season five’s “The Marine Biologist,” alongside George’s famous golf-ball story and Jerry’s elaborate lie about “War and Peace.”