Sounds like the questioner heard the line, "If Jimmy's a genius, I'm U Thant." spoken by the character Guy Patterson in Tom Hank's 1996 movie "That Thing You Do".
Considering the time period of the movie, the writer must be referring to the then Secretary General of the United Nations, Burmese diplomat U Thant.
The character even starts to answer TB Players same question with, "He's the Sec... forget it."