"Once in a Lifetime" is an extremely '80s song. When many people talk about the 1980s—especially the American culture of the time—it is with disdain or disappointment.
Why did we wear shoulder pads? Did people really spend $50 a week on hairspray? Didn't they know they were creating a hole in the ozone layer? And what were we dancing to?
Musicians like to balk at their '80s music, too; David Bowie says he doesn't want to remember those years. Dramas set back the '80s tended to focus on criticizing the yuppies—or young-urban-professionals—for their ruthless pursuit of the (white) suburban dream of a big house, a beautiful wife (that will obey you), and lots of money. A prime example is 2000's American Psycho (based on the 1991 novel of the same name), set in the late '80s, in which the yuppie main character is a mass murderer.
Some people even claim that the only good thing to come out of the '80s were those John Hughes teen movies like The Breakfast Club (1985) and movies and music that criticize the '80s like we do. A lot of writing about artists that are undeniably great but undeniably '80s has to do with making sure that they were aware enough in their music to only be ironically playing into '80s yuppie culture, so when Talking Heads wrote "Once in a Lifetime," that's what we got.
Many of us would like to think that the '80s were as ironic as the current hipster culture that emulates the Decade of Decadence is, but the truth is that people were just genuinely happy to be alive and doing crazy stuff to their hair, and maybe that's not such a bad thing after all.
Lyricist David Byrne wrote "Once in a Lifetime" like a religious sermon. He uses the cadence, timbre, and rhetorical techniques of preachers as his character sings about the realization of the great place the world is.
Byrne says, "So much of it was taken from the style of radio evangelists. So I would improvise lines as if I was giving a sermon in that meter, in a kind of hyperventilating style." That "hyperventilating style" that Byrne adopts reflects the passion and intensity of preachers.
Intensity is built up throughout the verses with repetition. Each line begins the same, employing the rhetorical strategy of anaphora:
And you may ask yourself: how do I work this?
And you may ask yourself: where is that large automobile?
And you may tell yourself: this is not my beautiful house!
And you may tell yourself: this is not my beautiful wife!
This pattern continues throughout the entire song, which is fitting considering that beneath the track is a looping the bass riff.
Another aspect of the preacher style shapes the chorus: call-and-response. Call-and-response is a musical technique where one melody line seems to respond to the previous one. Gospel music and gospel preachers use this heavily. A gospel sermon is more than a preacher talking to the crowd; the preacher will rile the crowd up to get them involved, feeding off their murmurs and comments, and then everybody breaks into song and dance.
Listen to the chorus and see how the melody of "Letting the days go by" and "let the water hold me down" seem to argue with each other. It builds a kind of reverent excitement and celebratory mood in the song.