Mike Love changed some lyrics for the Smiley Smile version. The original SMiLE sessions version had a verse about a speechmaking business man. It was originally titled "He Gives Speeches."
The "Sha Na Na Na" section is based off the Silhouettes 1958 #1 single "Get A Job." It turns "Get A Job" into "What A Blow," a coincidence that somehow convinced drummer Dennis Wilson that this song was about fellatio.
Humour was supposed to be a feature of Smile. The speeding up of "What a blow" and the humourous narration from Mike Love and Brian Wilson made this part of Brian's musical comedy concept.
Suggestion credit: John Jennings - Omaha, NE, for above 3