I am a big fan of science channels including Veritasium. In this one they tackle the question of “what does it take / what does it mean” to be an expert.
TLDR: a lot of deliberate practice at the boundary of your comfort zone. Plus of course a clear short-term feedback mechanism that rewards you when you get things “right”.
These days? You just go on twitter and start posting authoritatively about a subject, the less you actually know the more success you’ll probably achieve.
This is an interesting video.
In summary, the video asserts that becoming an expert requires some significant investment of time where the following conditions are met:
It feels silly to describe myself as an “expert,” but as somebody who has achieved some degree of expertise in several pursuits, much of this rings true for me. Just as an example, some of my recent comments have mentioned the importance of developing a robust feedback loop.
However, there are some important points which I feel were not mentioned.
Firstly, we must truly believe that the pursuit holds some value to us, be it personal or professional. If we don’t truly believe that the pursuit is valuable to us, we will not invest the necessary time and attention.
On the personal level, that value can be the sense of satisfaction and accomplishment in the development of our knowledge and skill. We may perceive the pursuit as having value to us socially. We may simply enjoy the process, and find fun in the pursuit. I genuinely believe that all of these factors are significant and important in reinforcing our commitment to the pursuit.
If we perceive the pursuit to have value to us professionally, it becomes easier to rationally justify our investment of time. It also helps us to invest time into the areas of our pursuit which are less appealing to us personally, but which have professional value.
Secondly, we must truly believe that we can continue to learn and improve our knowledge and skills. If we convince ourselves, rationally or emotionally, that we cannot achieve our goal, we will not pursue it.
Thirdly, we must not only be able to tolerate our mistakes and accept our failures. We must genuinely appreciate them as opportunities for improvement and development. We must recognize that our mistakes and failings are of fundamental importance to our learning.
Finally, we need to identify and assess the validity of our assumptions. This can be difficult, many of our assumptions are implicit and are revealed in our approaches and actions. We must be able to challenge those assumptions and change our foundations when we find them to be unstable. Many of these assumptions are informed by our own experiences, others by established canon or dogma within our field.
I’m coming to believe more and more that when we encounter an expert whose capability and performance seems incomprehensible to us, it is extremely rare that they are doing what we are doing and simply “doing it better.” Most often, they are doing something different to what we have been doing, which is naturally more amenable to achieving their seemingly incredible results. They may not be consciously aware of this, they may even believe that what they do is no different to what is commonly done or taught.
If we are able to identify and challenge our own assumptions, we are more able to identify a difference of degree from a difference in type.
@Tom_Gilroy agree on all your points and this in particular:
@Prlgmnr THANKS FOR THE TIP I’M ALREADY PRACTICING MY CAPS LOCK!
It’s curious that somehow your regular typing has an Italian accent, but your caps lock doesn’t.
Derp. Thanks @tommo for catching my repeat of your post and merging with your original topic.
I promise I paid attention to your post the first time around. I [checks notes], apparently even replied to it at the time??? Well, hopefully this doesn’t mean you can look forward to seeing even more of your posts from me in the future. 
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Video below talks about the nuances of expert performance, deliberate practice, and the Anders Ericsson “10,000 hour rule”.
TL;DR: Four key ingredients that are required for developing expert performance, beyond merely “putting in the time”:
A lot of this should sound familiar to those of us who have been paying attention to CTC’s findings and advice.
The video even has a guitar-specific nod at the end (to illustrate point 4).
In the good old days all you needed was a white lab coat 
My favorite description of expertise comes from the physicist Neils Bohr:
“An expert is a man who has made all the mistakes which can be made, in a narrow field.”