The trouble with piano study based on technique only is that listening is ipso facto left to someone else. This is not only demeaning for the student, as it denies the validity of the student's own ear, but it is grossly unfair to the composer.

Yesterday I had the experience of playing a Brahms duo sonata that I have heard and played many times. This time I decided to take Brahms's notation seriously and vowed to respect his note values as indicative of actual sound "values," so to speak. It was a different piece.

Among the more potent discoveries: 1) Rests, as in Mozart, are most often not pauses but indications of interrupted sounds.
2) Bass notes in extremely low registers affect the intonation of the clarinet and the ear of the pianist. (Am I alone to have found them problematic all my life?)
3) Much of what we accept as standard Brahms interpretation is simply the result of not paying attention: this music is incredibly multi-layered.

Boredom or inattentiveness, as usual, proved to be reliable guides in discerning the places that needed closer examination.