In the context of this article and GP post I think the teacher trying to coach students that the act of trying something/anything has the probability of the solution snowballing out of your head. But often students give up before trying and it's a marker's nightmare.

I've seen many people hand in a totally empty answer sheet (something I've also been guilty of in the past). During one of my organic chemistry exams, I saw another student break down because a lot of the questions were unconventional and I could hear the very kind invigilator trying to encourage them mid exam "if you don't try something you can't get more than zero".

I read another examiner report for a notoriously hard physical chemistry paper that it was too hard to fit examinees to a curve because there were too many blank answers and the marks were too low.