Another Theory On "Dr. Robert's" Identity

In his biography of Who bassist John Entwistle, Paul Rees attributes the
following to Entwistle's and Moon's driver Peter Butler:
"John and Keith used to go see a Dr. Robertson in Harley Street -- the
famous one the Beatles wrote about as 'Dr. Robert.'  They used to get
Drynamil and sleeping pills from him.  Because they were on
prescription, if you got pulled up by the police, you just got out your
little brown pill bottles,  John got off the uppers and downers after he
got married.  Humor bonded him with Keith.  They were both quick-witted
-- Pete [Townshend], too -- Pythonesque and all three of them would turn
any situation into a laugh."
My understanding is that Lennon's song "Dr. Robert" was actually about a
Manhattan-based Doctor Robert Freymann would who supply clients with
stimulants and/or help clients quit heroin.
In fact, when Yoko Ono decided to give up heroin in 1979, her reluctant
lover Sam Green took her to Freymann.  The amazing story is in Goldman's
book.