This study focused on the daily activities and related quality of experience of two distinct groups of Italian high school students analyzed in 1986 and 2000. Altogether, 120 participants, aged between 15 and 18, were administered the experience sampling method, a procedure providing on-line repeated samplings of daily time budget and associated quality of experience. In particular, attention was paid to optimal experience, characterized by a balance between environmental challenges and personal skills, intrinsic motivation, involvement, and well-being. In spite of the time gap, no major differences in the daily activity distribution were detected. Adolescents in both groups spent most of their time studying at school and at home, interacting, watching TV, carrying out maintenance, and engaging in structured leisure activities. The use of new technologies (computers, internet, mobile phones) emerged in the data gathered in 2000. As concerns the quality of experience, each daily activity showed a specific experiential profile recurring in both groups. Studying at home and engaging in structured leisure activities were primarily associated with optimal experience, as was using new technologies in 2000. These results shed light on students' preferential engagement in specific domains and allowed us to explore the active role of adolescents in shaping their future. Findings also highlighted the importance of providing adolescents with meaningful activities in order to foster their personal growth, well-being, and social integration.