It's very clearly stated in the film: You make your own choices, and what you're always fighting is ego.
“I would start seeing, in just the sense I was saying now, the kind of record it was going to be and what the arrangement demands, and what my vocal part should be in the record. This was all emerging as the song was emerging.”
“An object is not first imagined or thought about and then expected or willed, but in being actively expected it is imagined as future and in being willed it is thought.”