The interpretation of interpretation

I found Byron Janis' commentary on musical interpretation fascinating, and also encouraging, in a way.  As a conductor I feel tremendous responsibility to get the music right and honor the composer, but oftentimes for me the "score is a sacred document" philosophy can be paralyzing, especially with the great works in the orchestral canon.  Often I'll agonize over a transition or tempo change in a Classical or Romantic era symphony, resorting to complex calculations to determine phantom quantum-level tempo relationships, and in doing so loose all touch with my instincts and common sense.  So it takes a bit of the pressure off to learn that our great composers have taken a more relaxed approach to performing their own music.