Correct. Dennis was the original surfer and the drummer for the group. He died tragically. All the women went wild for him, ignoring the rest of the band members. He had a lot of behavioral problems. Also the whole Wilson clan had authority problems with the overbearing father who was a songwriter in his own right and who tried to control them musically. Brian was the one who was able to cut the group loose from the father because he had very original ideas about the music. Brian is/was a genius. Even the professional musicians who backed the group (The Wrecking Crew) on their later recordings acknowledged the originality of the young Brian Wilson. The Beatles themselves were also on record as acknowledging his immense talent and contribution to the genre.
He was the initial crazy one in the family, the way he treated the boys.
*** Brian Wilson’s work was admired by every part of the music industry, and one of his biggest fans was The Beatles’ Paul McCartney. The Beatles bassist named “God Only Knows,” as his favorite song of all time and referred to the track when asked about his melodic bass playing.
“God Only Knows’ is one of the few songs that reduces me to tears every time I hear it. It’s really just a love song, but it’s brilliantly done. It shows the genius of Brian. I’ve actually performed it with him and I’m afraid to say that during the sound check I broke down. It was just too much to stand there singing this song that does my head in and to stand there singing it with Brian,” stated McCartney in 2007 after having the opportunity to perform the song with Brian Wilson. ***
https://dailyrockbox.com/paul-mccartney-names-his-favorite-song-and-its-not-a-beatles-track/