I do think my students enjoy their flying and are willing to do well. when I learned to fly I was not allowed to land off centre line, the penalty was to be washed out of the course, but my students are all civilian so I need something to make them think and a little humour sometimes helps.
"You paid the taxes that let them paint that line, so use it!", "How considerate, landing on the side of the runway and not wearing out the paint," etc.
I still remember flying with a great inspector from New Zealand, as I flew down on a steeper than normal glidepath to the threshold of the runway in a HS748, "The only time you were on the VASIS, Boofhead, was as you went through 300 feet! Maybe I will recommend that they take it out, since you evidently don't need it!"