Supposedly, when John Lennon was asked if Starr was the best drummer in the world he replied, “The best drummer in the world? Ringo wasn’t even the best drummer in the Beatles!” [Referring to the fact Paul McCartney played drums on a few tracks] But Lennon didn’t actually say this.
I had read that after a day of recording, Starr left the studio and John and Paul would stay and mix the music, with Paul re-recording the drum tracks correctly. The next day, Ringo would come in and listen to the music silently, turning red as a beet with shame and anger.