Learning, Thinking and Thinking about Thinking aka Metacognition

“It ain’t what you know that gets you into trouble. It’s what you know for sure that just ain’t so.” – Mark Twain

Why? 

I am passionate about Learning and Knowledge(Just to be clear, I am not bragging that I am a learner or knowledgeable person. It's the process I am curious about). As usual I need to answer the why question at the outset and at a very basic level. Otherwise, this piece wont progress. 
Learning is not about intelligence or even basic cognitive capabilities. Even inanimate things learn. At least that is what my hypothesis is. For example light knows(?) to travel exactly at a constant speed. No more and no less. How did that happen? We can extend this argument to every observable behavior of animate and inanimate things. How did a Deer learn to run at the sight of a predator Tiger? All these can be explained with evolutionary theory. Any Deer that wanted to stand and fight a Tiger would have died a long time ago giving it no opportunity to leave an offspring for us to observe. Similarly an inanimate thing has its behavior because anything else would have been unstable and died off long time ago. May be there was an universe where light was traveling at different speed but it was unstable and got destroyed.
The point for the humans with cognitive capabilities is that if we don't continuously learn the right thing we will disappear.  Nature gives a long rope we can do a lot of stupid things and still not perish. That is why even when we do not know what is that absolutely correct way of behaving we are still able to survive. No one knows, no one would ever know or there is no such absolute correct way of behaving. But it is clear that there are many things which we absolutely should not do if we don't want to perish. Humans or anything for that matter will eventually learn, but the choices for us are, either we leave the control of learning process to evolution or take it in our hand and constantly learn so the pursuit of knowledge can be accelerated.
As a species named sapience( knows), not just knows but knows that it knows, it's an obligation for humans to continuously learn. Learn so we don't perish and continuously because knowledge is evolving continuously.
Fixed Mindset and Growth mindset.Then the question comes how to learn effectively? Learning is generally associated with intelligence and smartness. We celebrate smart people. But latest research suggests smartness is achieved via hard work and practice. The more we praise smartness/intelligence a person tends to assume since they are already smart they don't have to work hard for learning. This is called fixed mindset, and it results in sub-optimal learning outcome. But if we celebrate and praise the hard work and process of learning more than the outcome itself, a person tends to work hard and practice more and more for learning. This is growth mindset. Researchers have shown kids and adults with a growth mindset do much better in learning outcome compared to the ones that have a fixed mindset.
UnlearningAnother aspect of learning is the unlearning part. The moment one is so sure of what they know and become dogmatic in the face of evidence to the contrary, it becomes a downward spiral. We need to cultivate the habit of unlearning things that don't work anymore.
Metacognition
We learn not just by hearing a lecture or reading a book. We learn mostly by thinking about all that we have received and observed. In fact thinking goes deeper. Consider this.

“I am not who you think I am; I am not who I think I am; I am who I think you think I am ” - Charles Horton Cooley

Ok, that's too much thinking there. But will you dispute that 'Thinking' defines us. In that case, don't we have to understand how we think. That is what Metacognition. Thinking about thinking. We need to take a step back and observe how we think and how we learn facts and form opinions. When we understand that, it makes us less susceptible to bias, pseudo sciences, and fake narratives.