GANGNEUNG, South Korea — At the end of each lesson — and there have been hundreds and hundreds of lessons with Coach Tom Zakrajsek — U.S. figure skater Vincent Zhou bows to his teacher. Even on the busiest days at the Broadmoor Skating Club in Colorado Springs, when Zakrajsek must skate off to another section of the ice to start the next lesson with a waiting pupil while Zhou completes his compulsory cool-down laps, Zhou will skate to wherever his coach is before departing to bow in gratitude for the wisdom he has imparted. “That kind of respect is so rare,” Zakrajsek said in an interview this week.