I think I might have posted this before, so forgive me if I'm repeating myself.
It seems to me there are two seemingly contradictory things that happen when going through the recording process: you hear things that you don't need to hear, and you don't hear things that you should hear.
For example, you can spend hours mixing up minor mistakes, and not realise that the vocals are out of tune. It's a a result of the difference between 'expected' and 'unexpected'. Your brain can fool you into thinking that what you expect to be there is actually there, but reacts instead to what is unexpected, e.g. a funny note in a solo. From the perspective of the listener, who has not been soaked in the process, they hear what for you is 'unexpected' as simply part of the song, but they will notice what your brain threw a cloak of invisibility over. So there is a tendency to sweat over things that don't matter, and not deal with the things that do matter.