Inspired by Chuck Berry's 'Havana Moon' and the Mercer/Arlen composition 'One For My Baby (And One More For The Road)' along with maybe some other conscious or subsonscious sources Richard Berry wrote down the lines spoken by a homesick and lovesick Jamaican sailor, who explains to a barkeeper named Louie that he wants to go back to his darling he's left on his home island. Nothing much of a literary highlight, but THE perfect pop lyric. You have to sing SOMETHING, and as long as the chorus is catchy enough to be remembered after having heard it only once, the rest doesn't really matter.
That's the main reason that so many different versions exist, especially the Kingsmen's unintelligible version has lead to many phonetic interpretations and misinterpretations that have added a lot to Louie Louie's legendary status.
Back in 1963, everybody who knew anything about rock 'n' roll KNEW that the Kingsmen's Louie Louie concealed dirty words that could be unveiled only by playing the 45 rpm single at 33 1/3. Eventually the FBI got involved, conducting a thirty-month investigation that led to Louie's reputation as a dirty song. This investigation led to the following most common set of dirty lyrics, collected by the FBI in Tampa,Florida in 1964 (and often used by Iggy Pop in his renditions of the song)