Having a deep understanding of a subject allows you to express your knowledge in simple way.
'Simplicity is the ultimate form of sophistication' as they say.
Taking away the superfluous. Understanding how something truly works can lead you to a final end state that is a pure expression of its intrinsic value.
Those are the best writers*, the best products and best conversations. It gives you the big ideas, delivered in simple ways and does not add anymore than necessary.
If lack of knowledge is the father of complexity then ego is the mother.
Ego feels the need to add on unnecessary concepts, hype, or adjectives to demonstrate wanting value.
A PhD dissertation in a STEM field is about 200 pages. In Social Sciences it's closer to 300. Einstein's paper on that had the Theory of Relativity in it was 30 pages.
The more complicated someone tries to make a concept indicates either their lack of understanding or their lack of humility.
Be the person that wants to constantly take away the unnecessary. Minimalism is mastery.
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*I am roughly 4 billion miles away from being a good writer but I enjoy reading them.