Learning to play any musical instrument is challenging and the piano is no exception. Some people think playing golf is frustrating even if you have the best golf instruction book ever published. Even with the best piano instruction books, learning the piano requires time and patience.
Playing piano involves eye hand coordination in making complex moments of the body. Many of these movements are almost invisible. The energy comes the torso and radiates down the arms into the hands. It is not the movement of the fingers that is producing the music. It is energy being transmitted through your body that is producing the music. Focusing on your fingers will produced note centered playing which sounds dull and unemotional.
This rhythmic principle of energy channeling will produce sounds as soft as a pin drop to as loud as thunder. So loud and powerful that your audience will wear a black helmet to protect their hearing. You can recognize finger centered piano playing. It lacks the clarity of tone and expressive nature of piano playing produced by the whole body.
Spending endless hours practicing scales, arpeggios, and dull exercises will not give your this sound. Exercises which claim to build finger strength are particularly ineffective. The strength of your playing does not come from your fingers. It comes from the physical coordination and energy flow of your entire body. Once you have mastered this technique you will be able to get that quickness that needs a digital sport watch to time. It is a smoothness and power that the human ear perceives as beautiful music.
The old fashioned teaching methods of practicing at slow tempo and playing left and right hands apart must be abandoned. These teaching methods are counter productive. The eye hand coordination and motions required to play at the proper tempo are completely different and lacking when played at an artificially slow tempo. It is a complete waste of your practice time. The same is true with practicing hands apart. It is the coordination of the two hands that must be practiced and mastered.
There is no reason to practice boring scales and arpeggios. Real serious contain scales and arpeggios. It is an unpleasant waste of time to practice them. Simply play the beautiful music contained in the repertoire which contains all the scales, arpeggios and everything else you will ever need to know.
Remember fine piano playing does not come from the fingers. It is produced by the whole body creating the driving rhythmic flow that our bodies respond to. You learn how to do this by playing actual piano music instead of exercises which will bore the student.