You have to put the time in to really 'own' skills, but as many have pointed out, you can practice the wrong thing, or the right thing with no 'feeling' for years, and still have nothing.
Don't practice at all ... and you probably have nothing too ..... well, you probably have some stuff - can't turn your nose up at instinct ... but all the efficiency, the affordances, the seeing, and the counter intuitive stuff, yeah, that needs time.
So, you put the time in, but how do you put the time in?
Like with all things it is a balance. A balance of relaxed 'no thought', mindful action, and critical thinking .... and above all else, the motivation to actually keep practicing.
They say a student takes 3 years to find a good teacher, but 10 years for a teacher to find a good student, and the longer I teach, the more I come to understand the old stories of the teacher turning the student away many times before accepting them, or giving them boring and ridiculous tasks to try to get rid of them until they really, really show willing .....
I am not advocating this approach you understand, but I do see why these stories came about. There is stuff you just cannot get 'like that', and even the swiftest, brightest, most physically adept students must still really put the time in to see the true potential of what they initially just get a glimpse of.
So .... does that mean that there really is only a certain small percentage of students actually cut out to 'really get it'? To actually stay engaged enough to practice and engage their brains over months and years ...?
To put in the time?
And what part does the teacher/coach play in all this? Hopefully the coach motivates and creates a program worth following, or is an example worth becoming ... And here you start to see the potential pitfalls - of creating a mythic or mystical path up the mountain, or a feeling that the student is not worthy to gain the secrets that lie ahead ... at least not just yet ......
The teacher gains huge amounts of power over the student which almost seems bound to becoming corrupt.
The alternative? Honesty, and leaving the motivation in the hands of the student? Should they alone be responsible for their own progress? Is the teacher's role to just give as freely and openly as possible, show the possibilities as well as they can, encourage and ...... And, what ....?