We live in ignorance all day, every day. Ignorance is our common state, not rationality. Although rationality is something that may pop up now and then in our lives, it does not do so consistently and may fail us altogether at critical junctures.
If your reptilian brain can be convinced of its almighty ignorance, it may turn out to be the most rational thing it has ever acceded to. We live in ignorance. We can't know ever so many things, let alone what is going to happen to a stock's price in the next week. Ignorance is far different from stupidity. It's stupid to think you can know something that is not knowable, but it is far from stupid to recognize your own ignorance when faced with the unknowable. Indeed, knowing your own ignorance is intelligence.
...if your energy is not corrupted and depleted by a continuous attempt "to be right, to be smart, to know more, and most deadly, to want to be better," then your energy for seeing reality becomes vastly increased.
...if we get caught up in thinking that we can know the future if only we are just "good enough" and can gather more facts, or the right ones, and can then take the risk out of everything we do, then we are lost because we are living a lie. On the other hand, if we labor in ignorance as a matter of course, we are not then invested in this lie at all, but only in what is going on. This is freedom. You are no longer tyrannized by a mind that is overwhelmingly concerned with appearing smart to itself. The mind will act rationally when it is does not burden itself with trying to be something it is not. We live with "I don't know." So if we don't know, what do we do? Mitigate risk is the rational thing to do.(This is more trading specific) Ah, at times, when we are relaxed, we can be rational! Hooray for evolution! And so ignorance leads to brilliance, but had we started out wanting to be brilliant, all would have been lost and the Holy Grail would still be hidden from our sight.
Experimenting with rules on a contingent basis to allow for the better functioning of the evolving spontaneous formations of the extended order of human cooperation simply works better than any grand plan. By embracing our ignorance we can be brilliant!