It’s already past bedtime, so I’ll keep this quick. Here’s a bit of information from the Kwik Brain podcast, Episode 20.
Flow happens at the 45° angle directly between anxiety and boredom.
In other words, in order to reach that optimal state of performance, I have to be pushing myself, but not so far beyond my abilities that I’m paralyzed by my shortcomings. I need to both have an idea and the ability to just barely bring that idea to fruition.