Written by Brian Wilson and Russ Titelman, it is a love song that describes a man who regrets ending a relationship after he realizes he still harbors deep feelings for his former lover.

"Guess I'm Dumb" is a love song that describes a man who regrets ending a relationship after he realizes he still harbors deep feelings for his former lover.

[2] Wilson produced the backing track amid the early sessions for The Beach Boys Today!, on October 14, 1964, at Western Studio in Hollywood.

[8] Musicologist Philip Lambert wrote about "Guess I'm Dumb" in his 2007 book Inside the Music of Brian Wilson: After hearing Glen Campbell's sterling vocal on the final recording, it's hard to imagine "Guess I'm Dumb" as a Beach Boys song, and therefore easy to understand why it might have been passed over for the Today!

In every aspect, from the cumulative intro and distinctive drum beat to the colorful orchestration and certain specific chord progressions, it's Brian's most Spector-like production to date, and in fact shares artistic space with Spector's recording of "You've Lost That Lovin' Feelin'" for the Righteous Brothers ...[1]"Guess I'm Dumb" was released as Campbell's seventh single on Capitol Records on June 7, 1965.

[8] Biographer David Leaf referred to the song as "Brian's most ambitious outside production effort, and one of the first records that consolidated all his ideas into a coherent sound.

"[9] Writing in his book Sonic Alchemy, David Howard said "Guess I'm Dumb" was Wilson's "most inspired" production to date, featuring a "surging, elegant Burt Bacharach-inspired string and horn arrangement and Campbell's forlorn Roy Orbison-like vocal.

"[12] The song is featured on many Glen Campbell compilations, and appears as one of the many Wilson-produced tracks on Pet Projects: The Brian Wilson Productions (2003).