Understandable boxer. I played in my first all-original-material-band in ’71, and could not get the other guys to listen to my recent (’66-’71) Beach Boys albums. The image of them at that time was of their early, surf style music. There is actually some great music on the early albums, like "Don’t Worry Baby" and "In My Room".
Brian stopped touring with the band in ’64, stayed home and recorded the Pet Sounds album without the other members, using the best studio musicians in Los Angeles. He then overdubbed their vocals when the instrumental tracks were completed. The material and sound of that album is completely different from the earlier stuff. McCartney and Lennon flipped when they heard it, Paul himself considering it to be the best album he had ever heard, responding with the Rubber Soul album. Beatles producer George Martin considers it a landmark album. Pet Sounds has consistently been voted the best Pop album of all time in British polls, beating even the over-rated Sgt. Peppers Lonely Hearts Club Band. That album was Paul's attempt to equal the Smile (see below) tapes he had heard, one of the songs on that album he actually singing on ("Vege-tables").
Brian heard Rubber Soul and started working on the legendary Smile album, which is a very progressive, psychedelic masterpiece that ended up being shelved instead of released in early '67, as it was originally scheduled to be. It was finally released a few years ago in three versions, including a 6-CD (!) boxset. In 2003, Brian and his current band performed the Smile album live in London, people flying in from all over the world to hear it. McCartney was there.
Brian left The Beach Boys in the 1980’s, and after his brothers Carl and Dennis died, Mike Love took over the band. It is he who was responsible for the Kokomo, Brian having nothing to do with that dreck.