Nephew gave up drawing recreationally for almost a year after a
   teacher said he "obviously wasn't trying hard enough" to draw an
   owl in the 3rd grade. He really took it to heart. Took 9 months
   or so of gentle coaxing now and again and he started drawing
   again in the summertime. That kind of stuff can stick with you
   for a lifetime - a single comment at the wrong time.