This Sci-Am article suggests the right kind of encouragement and mindset are important in overcoming challenges for kids and adults. I tend to agree; although, I've seen some hard working students in my class struggle with conceptual problems while others who just "get" it.
At times, the intellectual hurdle seems too high to them and students think the effort required might as well be infinite; and therefore, they give up before they understand a concept or solve the problem. But it's exactly at those times where a little bit of extra effort can see real payoffs. That's something I've forgotten about lately too and could use the reminder. Note to self:
http://www.sciam.com/article.cfm?id=the-secret-to-raising-smart-kids&print=true