Refer to "LBJ," and you'll likely get a wildly different reaction based on the age of the person you're speaking to.
Anybody who's grown up within the last decade or so will instantly have their mind flash to Heat superstar LeBron James, who has won three MVPs and an NBA championship despite being only 27 years old. While he usually goes by his official nickname of "King James," it's not uncommon to hear people refer to him by his initials as well.
But to anybody who grew up in the 1960s, the mention of those letters brings to mind the original LBJ — Lyndon B. Johnson, the 36th president of the United States. The nickname was so synonymous with Johnson, who was in office from 1963 to 1969, that it was rare to hear him referred to by his actual name.
Just another sign that the times are a-changing.