The "10,000 hour" idea was popularized by Malcolm Gladwell in his book Outliers.
The take-away is that top performers in any field have typically invested 10,000 hours or more of practice into their skill, and typically in a deliberate and structured way that achieves results.
We learn how to get to this 10,000 hours in the best and most enjoyable way in my community: skool.com/guitar