This might be one of the sillier trivia questions, but I wondered about this since around age 5 with the Art Fleming version of J! Has there ever been a "John-John" moment on the show?
You know the modus operandi of J! since day one: the host reads the answer, then calls out the name of the contestant who buzzed in first. A "John-John" incident would be where the last word of the clue and the called-out contestant's name are one and the same. So the name is said twice in a row. Hypothetical example:
John Higgenbotham: "I'll take 60's Ballads for $200"
Host: "The answer is.. 'He recorded a tribute to the assassinated, in a hit titled Abraham, Martin, and John.' John!"
John Higgenbotham: "Who is… Dion?"
This of course could be any name, as long as it's the same. Now when I first thought this up a half-century ago (there was a kid who went by John-John at a day camp I went to), the concept was of a single-word answer, and THAT being the same as the name of the contestant. One-word answers are uncommon enough as it is, so having that be the same as the contestant would be a rare event indeed.
P.S. Be sure to catch J! on January 19th.