Repetition for emphasis

I've written numerous posts about my middle and high school orchestra director, Mr. D.  Like many music instructors, his personality was somewhat eccentric.  One of his most frequent quirks was repeating statements for emphasis.  Three examples:

• After passing out copies of Claude T. Smith's challenging composition, "Our Creed Is Our Shield," to the high school orchestra, he told me, "That piece has a wicked bass line.  A wicked bass line."  He was right.  It was one of the most difficult bass parts I ever played, requiring a lot of fast shifting in a key that doesn't come up often.
• During middle school, the orchestra mused about how difficult college classes must be.  Mr. D. stressed the importance of being prepared for final exams.  "If your homework average is an A, your classwork's a B, and you get a D on that test, your grade in that class is going to be a C.  Think about that!  You've never been graded that tough.  You've never been graded that tough."  He was generally correct about that.  Final exams carry considerable weight in nearly every college class.
• As a senior in high school, I spoke with another senior about how much homework we had to do, in addition to all the music we had to practice for an ensemble outside of school.  Mr. D. appeared suddenly, telling both of us, "Multiply that by 10, and that's what you'll be doing a year from now.  They just expect that in college.  They just expect that."  Fortunately, college didn't necessitate doing 10 times the amount of work I'd done in high school, but Mr. D.'s underlying point about having to prioritize and juggle responsibilities in college was accurate.

Although these incidents happened, as Mr. D. would have said, "a long time ago...a long time ago," the accuracy of his advice and observations has stayed with me, and, I suspect, many other students, for decades.  When you remember not only what someone said but how he said it, that's a sign of an effective communicator.  His repetition only strengthened the impact of his statements.