How to Master Anything: PEAK by Anders Ericsson | Core Message - YouTube
The central message: The right sort of practice ("deliberate practice") carried out over a sufficient period of time leads to improvement.
A common learning obstacle: If you reach a skill level that feels “satisfactory” to you, you stop improving, and even get worse with time.
Mental Representations: Your skill in anything is based on the number and quality of “mental representations” you have for the skill.
Deliberate practice is even better than purposeful practice: