Gordon MacDonald writes:

As a seminarian, I was asked to write and deliver a paper to a special forum of students and faculty. Typical for me, I put off writing the paper until the deadline loomed and then cut two days of classes to complete the assignment. When I had finished reading the paper and the audience had responded with applause and left the auditorium, a professor whose classes I'd dodged in order to write the paper found me and said, "Gordon, that was a good paper, but it lacked the possibility of greatness. Do you want to know why?"

I could hardly say no, and so he continued. "You sacrificed your routine responsibilities to write it," he said. "Your ministry will not be successful if you make this sort of a thing a habit."

You listen carefully to an insight like that when it comes from a man 40 years your senior whom you respect. He was less interested in the content of my presentation than he was the character pattern that framed its writing. The paper would soon be forgotten (I can't remember anything about it now), but the work habits it revealed would continue the rest of my life if I didn't alter them.

He saw this; I did not. His rebuke caused me to reform my work ethic.