One of the two of my favorite people in the world noted how he didn't realize that his early adherence (pre-college) to mental practice was not normal.
I completely agreed that this was totally abnormal, my confidence in this assertion due to being in the majority of fellow piano collegians who disacknowledged the very existence of mental practice. This was while we were constantly harangued by our instructors about the importance of such a fundamental method of musical learning.
As I was so deficient in maturity at that age, how he displayed the emotional cognizance to do such a thing was astonishing (to top it all off, he apparently needed no external impetus).
Naturally, he wondered why it was so hard for his colleagues (my ignorant self included) to latch onto the significance of mental practice.
I responded with the following sentiments:
The nature vs nurture debate has been done to death, but one concept I hold onto as near-universal fact is how hard it is to not be immensely influenced by your external environment. Thoughts of my recent trip to Japan come to mind - imagine an entire culture that actively persuades you to abide by the conformity of the status quo (this exists in America to some extent, but good or bad it's still largely the land of the individual).
At my college, of which my aforementioned fellow is an alma matter of, the practice rooms all had windows on the doors. Meaning it was always transparent to the outside observer what you were doing inside. I experienced this habitat as a form of productive peer pressure, but now can see how it made it nearly impossible to engage in mental practice even if you wanted to.
Because if you did, you'd be that solo weirdo staring at your score and physically miming in the air while your fellow students around you were busily banging away at the keys.
What underscores all of this is how society generally rewards "visible" productivity, which in this case could be interpreted as "audible." In other words, if people don't see - or hear - you actually doing something, then you must be doing nothing.
I can personally attest to the frustration that quiet people or introverts experience when their silence is misinterpreted for laziness or listlessness. In actuality, they are furiously working away inside their heads either to solve a problem or gather thoughts for the appropriate words to come out.
Lastly, our outdated primitive minds have not caught up with this rapidly changing civilization. This makes us easy prey to a modern world which has become elite-level in both distracting us from our most important work and incentivizing us to busy ourselves with shallow work that almost anyone can duplicate (quantity over quality).
So when you undoubtedly feel like a loner standing against a vast system, remember what David Allen says. To paraphrase, you'll do your most important work away from the computer.
As a pianist, you'll do your most important practice when you're not sitting on the bench.
Cheers.