When Pablo Casals, the cellist, was ninety-one years old, he was approached by a student who asked, "Master, why do you continue to practice?" Casals replied, "Because I am making progress." As we learn it is natural to hit plateaus from time to time. Through mindful practice we can progress through the plateaus, and onwards up the mountain.
The Master brings patience, consistency and perceptiveness to the journey.
 Norman Doidge, The Brain that Changes Itself, page 258, my favorite non-fiction book for 2008.