"Master, if i practice diligently, how long would it take me to become adept at it?"
"Perhaps ten years"
"My father is getting old and i must take care of him. If i work far more intensively, how long would it take me?"
"In that case, it might have to take thirty years."
"You first mentioned ten years, and then you said it takes thirty years. I do not mind undergoing whatever hardship. I must learn it within the shortest possible time."
"Then you would need seventy years to master it"
More haste, less speed
Those who are too eager for results are apt to end up not having achieved anything. "Ordinary-mindedness is the way" means exactly this.