I have had a couple good instructor generated distractions along the way. I was getting a checkout in a Taylorcraft BC12D in Indiantown, FL. I was doing some nice landings. On short final, instructor pulls out a sectional, unfolds it, reaches across the cockpit for something, a bunch of crazy stuff and I blew the landing. Then I recovered. Distraction stopped, he says "That's what I wanted to see, a recovery." Signed me off good to go. He was an Englishman, I always wondered if that was standard fare on the other side of the pond. Bit of an oddball, very good pilot.
Back when I was towing, but had not earned my private pilot glider license yet, I was doing my pre-season checkout with Rudi Opitz. Most club instructors treated me like I already knew what I was doing, since they knew me as a tow pilot, even though I knew this wasn't the case. Not Rudi. We get off tow, he has me doing a bunch of stall series. Seems reasonable for a spring checkout activity. After the third or fourth he asks me where the field is. I turn toward it, knowing right were it was. Uh-oh. We look a bit low. As we flew back and did a nonstandard pattern due to altitude, he explained the importance of always knowing where you were with respect to the field and glide distance, even if an instructor was asking you to do things like stalls. That lesson hit home for me.
-- IFMU