He's probably using "smart" in the sense of "accumulated knowledge in a particular space" instead of in the sense of raw mental horsepower. http://news.ycombinator.com/item?id=3583985
Yes, that's right. It doesn't mean that you are hopelessly non-cognitive if you can't understand the complexities of cryptography. (As I said, I certainly can't.) It just means that unless you are one of the very few people who are 1) exceptionally mathematically talented and 2) able to have spent your entire life studying the subject, it's unlikely that you could make an informed choice.