Trivia

The real Wilson reported having a mild dissociative experience while watching the film. He started to believe that Paul Giamatti was the actual Eugene Landy and felt "absolutely in fear" for several minutes.

The studio scenes were improvised in a live, unrehearsed pseudo-documentary style with two 16mm handheld cameras. Paul Dano, who once played in a band, was really directing the actors on how to play their instruments, who themselves were also real life musicians. While these scenes were mostly unscripted, Dano directly quoted some lines spoken by Wilson from the original session tapes.

During the Q&A at the film's premier at SXSW '15, Brian Wilson stated that his favorite scene in the movie was the intimate scene between Cusack and Banks, reflecting a happy moment between his real life wife and himself.

Bill Pohlad said that real footage of Brian Wilson was included in the film to prove to doubting audiences that Wilson really does act the way he is played by John Cusack and Paul Dano.

The Beatles song referenced by Wilson's brothers was John Lennon's "Girl" from the album "Rubber Soul". It was one example where the Beatles began displaying prominent The Beach Boys influence in their music. Taking inspiration from the cohesiveness of "Rubber Soul", Brian then set out to make "Pet Sounds" an album with no filler tracks. The Beatles then responded to "Pet Sounds" with "Revolver" and, more famously, "Sgt. Pepper's Lonely Hearts Club Band" after Brian failed to complete "Smile".