You can do what you have to do, and sometimes you can do it even better than you think you can.
I still like to keep tapes of the few minutes before the final take, things that happen before the session. Maybe it's superstitious, but I believe if I had done things differently - if I had walked around the studio or gone out - it wouldn't have turned out that way.
The arts are not just instantaneous pleasure - if you don't like it, the artist is wrong. I belong to the generation which says if you don't like it, you don't understand and you ought to find out.