A recurring theme in flow interviews across very different fields is that the activity, described from outside, looks like a contest against an external opponent or obstacle — a mountain, a competitor, a deadline — while the person actually inside the experience describes it as a contest against their own prior limits. This reframing matters because it shifts the goal from "beat the external thing" to "discover what I'm actually capable of," which is a subtly but importantly different and more sustainable source of motivation.
This self-referential framing also explains why flow activities remain engaging indefinitely, in a way that purely externally-defined competition often doesn't: an external opponent can eventually be beaten and the challenge exhausted, but the project of discovering your own expanding limits never runs out of new territory.