"Wouldn't It Be Nice" describes a young couple fantasizing about the romantic freedom they would earn as adults. Journalist Nick Kent felt that, although Wilson had captured similar "teen angst dialogue" with "We'll Run Away" two years before: "This time was out to eclipse these previous sonic soap operas, to transform the subject's sappy sentiments with a God-like grace so that the song would become a veritable pocket symphony." Asher said that it was the only song on the album in which he wrote words to a melody that Brian had already finalized. The exact degree of Love's contribution was never fully determined, but under oath in a court of law, Asher stated it consisted of the line "good night my baby / sleep tight, my baby" and possible minor vocal arrangement.