I am again reading through the excellent The Edge series of answers to What important tool should you have in your cognitive toolkit? . This is one of the most important series or articles/post that I've ever read online or offline. Not only because they found legions of really smart people, which gives you, predictably, lots of good answers, but because you can contrast what is important to each one of them, and how one tool interacts with the other.
At this time, I just finished reading Evgeny Morozov post, about the Einstellung effect. To summarize, this is the realization that as pattern recognizing machines, we always have the tendency to try to solve a problem with the tools that have worked on previous seemingly similar problems, without stopping to think if the problems are actually the same.
After reading his contribution, I realized that this is actually a meta-cognitive tool, that you have to use on top of the other ones. And it is very important because it has to counteract so many of our natural tendencies. It has to fight against cognitive dissonance (we used this solution before for something that looks just like this, so if I use another one I will look stupid, therefore I have to use the old solution), against confirmation bias (yeah, this old solution worked great for that problem...what? it didn't? Nah, that must be wrong) and so many other cognitive biases.
And I also realized that it is very hard to use, unless you do it on a systematic way, as it will always add extra time to your thinking, and it may not give you any benefit (you may actually be right in selecting the old answer). Therefore in our never ending battle for efficiency, we may be confronted to the hard decision to either use this tool and expend more resources than expected, or ignore it to our own peril.
Then just after this last paragraph I realized the most important realization brought to me by Mr. Morozov post, which is that due to the bound nature of our rationality, we may need to ignore in some cases some cognitive tools. Which ones and when? Well, that's why we have Science and Philosophy. And that is why these two disciplines are always liked to have other people criticize you, because their bounded rationality may have used the tool that you missed, and discovered the hole in your reasoning.