I loved that song. It was written in the classic John Lennon style; take a simple melody and make it better.
A lot of short, repeated notes in the verses.
John is singing about Prudence, Mia Farrow’s sister, who didn’t want to mix with any others in the small group that traveled to India in order to meet a famous Yogi.
I think Lennon was angry because the Maharishi put the moves on Prudence, so she was reluctant to come out. He could no longer respect him as a spiritual leader, but Harrison loved him. #metoo
A famous Yogi that later on the Beatles got hip to.
He was a fake.
https://www.tmdeception.com/tmd-blog/2020/1/6/maharishi-fraud-amp-voodoo-science-an-open-letter-to-david-lynch-part-2
He made a sexual advance on Mia Farrow. Hence John’s song, Sexie Sadie, which was about just that.
https://en.m.wikipedia.org/wiki/Sexy_Sadie
The song Sexy Sadie was written about the Maha Rishi (sp?). Instead of saying “Sexy Sadie” the original lyric was “Maha Rishi”. John was very disillusioned after a two week visit to the Yogi's compound. The Yogi turned out to be a phony “holy man” who hit on a chick in their group, maybe it was Prudence. The reason John changed the lyric to "Sexy Sadie" was because George, who still thought the Yogi was the real deal, refused at the last minute to record a song that defamed him. If you change the lyric to Maha Rishi when you listen to it you'll know exactly what John thought of the phony holy man.