If you aren't familiar with FLOW as defined by "American psychologist Mihaly Csikszentmihalyi (Mee-high CHICK-sent-me-high-ee)." You should look into his books. As a primer read this article in Fast Company.
As learning professionals we (at least I do) work under the idea that motivation is absolutely critical for learning to be effective. So as a learning community we should be very interested in how we can develop learning experiences that not only engage but put learners into a state of FLOW.