I challenge this assumption. I have a very well functioning, blissfully optimistic mindset that I can load when my rationality suggests that this ignorance is indeed my best defense. I wish I had the skill to understand how I reconcile this with the rational compartment in my mind, but the two do seem to co-exist quite happily, and I enjoy many of the perks of a positive outlook.
Well, I don't and I can't. And I strongly doubt I could ever learn anything like that no matter what.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
If continuing the discussion becomes impractical, that means you win at open threads; a celebratory top-level post on the topic is traditional.