She talks about how deliberate practice is almost never enjoyable because you're trying to improve specific things, but it is how you attain mastery. The other side is "flow", when that mastery is display, and she mentions how it can look so effortless for top athletes, when it's almost definitely the result of hours and hours of deliberate practice.
I have become convinced that the idea that deliberate practice is not enjoyable is entirely mistaken and results from incorrect framing and insufficient focus on the task. One must discard all notions of the greater goal or sport and design a new game around the simplest aspect which requires improvement.
By practicing meditation and mindfulness, you slowly learn to find skillful movement in all activity. When you can derive pleasure from the mundane - when all movement becomes a dance, you eliminate the distinction between plateaus and play, between practice and performance.
I reject outright the notion that my personality is innately autotelic. It is a skill and a mindset that I've cultivated slowly and intentionally, and it's the difference between sticking with a goal and loving the journey.
Shows many examples of how deliberate practice on the edge of your current ability is what equals mastery ( whilst also exploring the science behind it )