The Sonata vs. Variations or Variations Within Sonatas?

Many years ago a very bright high school student came to his piano lesson and, smirking with delight, recounted that on a Music Appreciation test he was supposed to identify themes A and B of some symphony or other.  He found this quite amusing since they were actually identical, the "second"  merely a slight variant of the first. Of course, he couldn't have pointed that out without failing the test.

How many people go through life thinking that the point of listening to a sonata is to identify themes A and B and to recognize them when they return?  The whole entire point of the form is to make repetition impossible by change of key and other subtleties that heighten every volatile aspect of every element of the sound at any given moment.  The better the composer, the truer that is.

One is incapable of a simple repeat because the idea demands imagination and because it is not permissible to allow tedium to enter the experience wherever you are seated, whether in the audience or on the piano bench.