For much of the lyric content, Wilson turned inward and probed his deep-seated self-doubts and emotional longings. Brian's wife Marilyn felt that her relationship with Brian was a central reference within the album's lyrics, namely on "You Still Believe in Me" and "Caroline, No". According to Asher, he and Wilson had many lengthy, intimate discussions centered around their "experiences and feelings about women and the various stages of relationships and so forth". This included Wilson's doubts about his marriage, his "sexual fantasies", and "his apparent need to get with sister-in-law Diane."