What's the most memorable feedback you've received about your playing?

When I was 16 and had just started studying with my first professional piano teacher, she had a little student recital at her home. I played Chopin - can't remember what exactly; I think the etude in octaves Op. 25 No. 10 which I had just learned at the time. Afterwards, several members of the small audience came up to me and said complimentary things, and I - not satisfied with my performance - invariably answered something like "thanks, but it really wasn't very good at all". My teacher overheard that and admonished me at the next lesson to never reply like that again. She said: "These people told you how much they enjoyed your performance and how grateful they are for the music you played for them. Why would you take that away from them? Your only job is to smile and say thank you, not to invalidate their experience by telling them that they don't know what they're talking about.". She was so seriously upset with me that I've taken that to heart for the rest of my life. When someone says something nice about my playing (or singing), I try to always thank them and accept the compliment, no matter how happy or unhappy I may be with how I think it went. 

the most memorable comments from my teacher:

- "Rubato is like pizza dough. You can stretch it so thin that you can see the tablecloth through it, but if you stretch it too much, it breaks. You can put it back together, but it doesn't bake the same." 

- in reference to taking musical risks: "Sometimes you've just got to jump off the cliff and hope that you spread wings on the way down". 

Man, I feel like I've experienced some version of almost every one of these posts.  We probably all have.  There are also the things people didn't say.  

Anyway, the comment that stuck with me came from the neighbors in our apartment building.  I was very self-conscious about other people hearing me.  I expected outraged telephone calls every evening.  Well, they did complain.  Vehemently.  They liked listening to me so much that they complained when I did NOT practice.  Then I went from self-conscious to completely paralyzed.  

When I had been taking lessons for a few years (I was about 60 at the time), I was playing something loud and dramatic - at least I thought it was - and my teacher says "How loud would you say you are playing?". Well, that made me pause and think - and lead to an interesting discussion about dynamics, controlling my sound, cushioning those big chords, shaping my phrases, and so forth.

The best teachers know the right question to ask at the right time!

A teacher recently said to me: "I'm really proud of you!" I'm OLD and the teacher is YOUNG yet, to my great surprise, these words meant the world to me. I remain grateful for them and  for the possibilities these piano lessons opened up in my life.