I started reading the book, very good so far.
Re "there still would be uncountable numbers [of worlds] in which he was not only happy but his theory won the Nobel Prize"
Not too similar to this world, where the Nobel Prize is never given for theoretical speculations unconfirmed (in this case perhaps unconfirmable) in the lab.
See also the film "Parallel Worlds, Parallel Lives"
https://vimeo.com/58603054