He didn't just describe the flow state, but also identified the conditions to achieve it. One can modify their experience according to these conditions to enter a flow state. For example, when the problem you're working on is too hard, then first work on a simplified version; or make it harder if it's too easy! When feedback cycle is long, then first make it shorter, e.g., make tests run faster, etc.

I highly recommend reading his book “Flow: The Psychology of Optimal Experience”.

Rest in peace sir.