As someone who once made their living as a scientist, I can tell you from firsthand experience that while this is technically correct, the conclusion PG wishes to draw from this:
> One of the most effective techniques is one practiced unintentionally by most nerds: simply to be less aware what conventional beliefs are.
is very wrong, at least in the domain of scientific research (and probably others as well, but scientific research is the area in which I can speak with some authority). In order to make scientific progress, you have to understand the conventional wisdom. The reason for this is that the conventional wisdom in science is the product of about 350 years (and counting) of hard work by an awful lot of smart people. Those people explored a lot of wrong ideas on the way towards discovering the right ones, and if you are unaware of this history and just strike out on your own thinking that you are so much more brilliant than any other human who has ever walked the planet before you, you are much more likely to go down a well-known dead-end than you are to discover something new. I wasted about ten years of my life learning this lesson the hard way.
Being skeptical of the conventional wisdom can be useful, but keeping yourself intentionally ignorant of it is generally a bad plan.