Oh dear. This is really all sort of sad, as I think at least some of us are not listening, and this is really a rather important topic -- not the memorisation part, but the interpretation part.
First, a credential or two: I am, at best, a so-so pianist; I only switched to piano a few years ago when I retired. I spent 50 years as a Minister of Music; organist and choral conducting. At least moderately successfully. My own conducting professor -- back in the dark ages -- had studied with Nadia Boulanger, and I have had the opportunity to take master classes with a several reasonably well respected orchestral and particularly opera conductors. I am sufficiently egotistical to think that I do know what I am doing; I am not sufficiently egotistical to think that I always got the results I wanted! Once in a while...
It is always worth the effort to determine what a composer really wanted. This is why we study music history and musicology as part of becoming a usable conductor or interpreter. It is not, I would point out, always easy to do this -- even Mozart was rather sketchy when it came to interpretive notes in his music, and before him... almost nothing. Some later composers are very precise indeed -- Poulenc being a notable example. Others -- Sibelius and Puccini for example -- are not. It is also worth studying and listening to what other interpreters have done -- not so much so you can slavishly imitate someone, but to see what the possibilities are.
Having done all of that, it is imperative that the performer -- and it doesn't matter whether he or she is the conductor, soloist, or a member of the chorus or third violinist -- bring his or her own soul to the music. If you do not, the music is dead because you are dead, so far as the music is concerned. Perhaps you should not go completely against the composer's indications in the score; if you do, you are perhaps not fully respecting the composer's wishes. But interpreting those wishes is not only legitimate, but essential. A good composer -- and I've known several -- is always interested in the dialogue between his or her imagination and soul, and yours.
One of the saddest things about some of the "prodigies" I've heard over the years is that while they are frequently technically superb, the music doesn't sing. As an example -- and I don't think they would mind my mentioning it -- I distinctly recall a conducting seminar I was in many years ago with, among others, Michael Tilson Thomas and Seiji Ozawa, this being long before they were famous (and quite deservedly!). They were both struggling with finding out how to project their own interpretation of the piece, and finding that it is easy to keep time and get the right dynamics and all that -- but very very hard to get your soul into the music.
Think about it...