How often do you experience the mental state of “flow” when you are learning a foreign language?
"The evidence includes work by Csikszentmihalyi (1991), who introduced the concept of flow. Flow is the state people reach when they are deeply but effortlessly involved in an activity. In flow, the concerns of everyday life and even the sense of self disappear—our sense of time is altered and nothing but the activity itself seems to matter. "(Stephen D. Krashen)
http://www-bcf.usc.edu/~genzuk/Free_Voluntary_Reading-Krashen/FVReading3-Krashen.pdf