Chopiabin wrote:
“I completely disagree with Bernhard. If we were simply into practice for its athleticism, then why would we ever want to learn more lyrical and less physical pieces like Chopin's nocturnes? Of course, learning a fast, difficult piece is fun as well, but we usually practice so much because we are in love with what we are learning. Practice has never felt like practice to me - I love every minute of it because I know I am progressing musically.”
There is no need to completely disagree with me

. In fact I completely agree with you

. I am just adding something to what you said.
As I said, enjoyment of music is important, but I doubt it will get you through the drudgery of practice (playing a piece is very different from practising a piece). I still maintain that enjoyment of the physical process of playing – although rarely mentioned – is a very important if not the most important factor in keeping up with the practice necessary to learn and eventually play a piece.
The physicality involved in playing a piece is rarely mentioned because it is mostly unconscious. Consciousness is small, you can keep only so many items in it at any time (I am told it the maximum is seven plus or minus two). For instance, as you read this sentence, are you conscious (aware) that your eyes are moving? Are you aware that your feet are pressing the floor? Probably you were not, until I mentioned it. But for you to become conscious (aware) of these unconscious items (which were nevertheless there) something else had to drop out of your consciousness – like say the meaning of the text you were reading.
I suggest that some people naturally love the physical sensations associated with playing the piano – even though they may not be aware of it. They keep coming back to it for more and more practice, many times thinking it is because of their enjoyment of the music – simply because enjoyment of the music is what is foremost in their consciousness. Other people hate the physical drudgery, and this hate is likewise unconscious. So they cannot bring themselves to practise, no matter how much they may love the music, and are forever procrastinating and avoiding practice.
The solution to this problem - if indeed this is the problem - is to bring one’s awareness – at least momentarily – to the physical sensations of playing. Like I did when I mentioned the pressure of your feet on the floor. If this is the case - an intense dislike of the physical aspects of playing - once one is aware of such feelings one may be able to grind one’s teeth and decide to put up with it. And who knows? One may even experience pianist’s high and start enjoying it!
In fact I have heard of the opposite case: some pianists that in certain pieces will become so involved with the physical sensations of playing that they do not know what they sound like. They think they played beautifully, when that was not the case. And some pianists – again in certain pieces – will go to the extreme of recording themselves to listen to what they actually sound like.
None of this diminishes in any way the importance of being in love with the more musical aspects of what you are learning as well.
Finally, as for slow lyrical pieces, they have their own physicality as well. Have you ever heard of Tai Chi Chuan? Or Yoga? People who hate marathons and strenuous physical exercises tend to be attracted to these alternative sorts of physical activity. Not wishing to belittle their other dimensions (practitioners of these arts tend to wax lyrical about their spiritual aspects as much as pianists like to wax lyrical about the musical aspects of their pieces), I still maintain that in order to learn yoga or taichi, you must enjoy their particular physicality. So even for a slow lyrical piece (perhaps even more so!) what I said still stands.
Best wishes,
Bernhard.