Sometimes the most important concepts are the most elusive.
Every violinist, during some period of his career, has experienced great difficulty in arriving at systematic study—systematic, in the sense of throwing aside all work which his own experience has proven fruitless or, at best, barren of significant results; systematic, in reducing all technical difficulties, whether of the bow arm or fingers, to their simplest form, and building on such material the structure of his future achievements. Indeed, it seldom happens that a very young student discovers the true road to artistic attainment. Often, many months, if not years, are lost irrevocably. The pupil learns, in a general way, innumerable études and solos: he does not become acquainted with the vital principles which underlie all that he is attempting to accomplish. He tries to reproduce, parrot-like, what his teacher illustrates. The why and wherefore are seldom touched upon; and the result is that the reward of a talented student's conscientious work is deferred, and his struggles are unnecessarily prolonged.
— from
True Principles of the Art of Violin Playing by George Lehmann