Too rushed to learn

A young man went into the deep mountains to ask a master to teach him swordsmanship. He asked the master how long it would take to learn, to which the master replied "ten years". The young man said "my father is getting old, and I need to take care of him. If I am very diligent in learning, how long will it take?"The master replied "That way will take thirty years". The young man was even more anxious. "First you said ten years, now you say thirty years. I don't care how much hardship I have to bear, I must learn it in the shortest amount of time." The master replied "In that case, it will take seventy years".