> However, the perverse situation that can (and does!) occur is when people don’t know what they don’t know. In being naive, in not doing the above analysis, in making a quick decision, and in choosing to “use your gut” and make a decision, you limit your options. You loose the opportunity to address weaknesses in your knowledge.

As an interesting aside: "Not knowing what you don't know" is known as second order ignorance or the Dunning-Kruger affect [1]. The "orders of ignorance" beyond this one stage are quite interesting when analysing how we learn. Andy Hunt describes this in great detail in "Pragmatic Thinking and Learning".

I have always suspected it's possible to reduce your propensity for 2nd order ignorance through more varied learning. For financial decision making I can imagine this as a key meta skill where you must identify unknowns quickly and accurately and be able to intuit their potential impact... as each decision can appear to have very little in common to previously encountered ones such that knowledge accumulation alone does not result in significant accumulation of skill.

[1] https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect