Model abilities of successful persons you admire
For most of my adolescence and young adulthood, I fantasized about being a musician. A rock star, in particular. Any badass piano song I heard, I would always close my eyes and envision myself up on stage playing it to the screams of the crowd. People absolutely losing their minds to my sweet playing on the piano. This fantasy could keep me occupied for hours on end. The fantasizing continued up through college, even after I dropped out of music school and stopped playing seriously. But even then it was never a question of if I would ever be up playing in front of screaming crowds, but when.