- There are seven different Wilsons who were at least once credited for (co-) writing a song recorded by the Beach Boys: Brian Wilson, Dennis Wilson, Carl Wilson, Murry Wilson (as Reggie Dunbar), Karen Lamm Wilson (Dennis's wife at the time), Ron Wilson (not related) and Turner Wilson Jr. (not related).
- Lyricist Tony Asher originally wrote the lyrics for the song "Caroline, No" as "Carole, I Know". Brian misheard it.
- The girl you hear on "County Fair" is called Andrea Carlo. Even though she was just 17 years old, she was David Marks's aunt (he was 14).
- Dean Martin was Carl Wilson's father-in-law.
- The album "Sunflower" was rejected twice by Reprise Records before they finally agreed to release it. Just five of the fourteen original songs made it to the final version of the album.
- The most prominent voice on "Barbara Ann" is Dean Torrence of Jan & Dean. Due to legal reasons he couldn't be credited, but you can hear Carl say "Thank you, Dean" at the end of the song.
- In November 1969, just 200 people showed up for a Beach Boys concert in Mitchell, SD.