The authors defined optimal experience as a functional state of a relatively high level of concentration, time distortion, satisfaction, and enjoyment (Csikszentmihalyi, 1992) and collected data through the Day Reconstruction Method. In three random days, 147 fifth-grade students answered questionnaires for each school event in the previous day resulting repeated data from 2,288 episodes. Several hierarchical linear models were conducted. The authors found that elementary students perceived better quality of optimal experience during break time versus classes taught by activity, seatwork or lecture methods. Unexpectedly, more optimal experience was reported in the events when students perceived themselves as having high skill but low challenge, contradictory to the original expectation of skill-challenge balance. Four additional flow conditions were more effective than primary flow condition and instructional methods in predicting optimal experience. Finally, optimal experience varied much more across event-episodes than among individuals meaning that teachers have rooms to improve students' optimal experience in elementary school days.