It is important to set realistic expectations. The popularity of different programming languages is note purely random or an historical artifact. Some languages are easier to learn than others. If a student struggles to grasp an "easy" concept, she might give up prematurely.

I've witnessed this a lecture: the Professor tries to sell Haskell with the dreaded quicksort one-liner. In my opinion, that's the classic show-off example where it's easy for somebody who knows Haskell but hard for somebody who doesn't. Most of the class thought "obviously this is beyond my capabilities" and tuned out.

Of course, students should also know that hard problems are overcome by effort, not intelligence. I know the effect you're talking about, but it is a good habit to consciously not try be discouraged by hard problems.