I Know There's an Answer

"I Know There's an Answer" (alternately known as "Hang On to Your Ego") is a song by American rock band the Beach Boys from their 1966 album Pet Sounds. Written by Brian Wilson, Terry Sachen, and Mike Love, the song was inspired by Wilson's experience with the drug LSD and his struggle with ego death. Musically, it is distinguished for its colorful arrangement, unorthodox structure, and bass harmonica solo. The instrumentation also includes guitars, tambourine, tack piano, banjo, clarinets, flutes, electric keyboards, and timpani. Wilson, Love, and Al Jardine trade the lead vocal, for which the melody spans two octaves.

The subject matter was unusual for rock music of the era. Originally titled "Let Go of Your Ego", Love refused to sing the first draft of lyrics, recalling that they had promoted the use of LSD. After voicing his objections, Wilson allowed him to revise the song's message to be about finding meaning within oneself and allowing others to live as they wish, despite having reservations against those who abuse LSD as a form of escapism.

Love was not granted an official writing credit for his contributions to both "I Know There's an Answer" and "Hang On to Your Ego" until 1994. An earlier mix of the song, featuring the group singing the "Hang On to Your Ego" lyric revision, was released as a bonus track on the album's 1990 CD reissue. Session highlights were released on the 1993 box set Good Vibrations. Further highlights from the vocal sessions were released on the 2016 box set reissue of Pet Sounds.

Cover versions of "I Know There's an Answer" have been recorded by artists such as Sonic Youth and the Pixies' Frank Black, the latter using the "Hang On to Your Ego" lyric.