To what extent do childhood experiences of music practice influence thinking about music later in life? In this contribution, 27-54-year-old monozygotic twins discordant with regard to piano playing in life were interviewed about music experiences during childhood and adult years. Recordings of heart rate variability were performed continuously during the interviews which were done separately with playing and nonplaying cotwins. Random factors had determined whether the twin chose to play or not. The rationale behind using monozygotic twins was that this offered a possibility to account totally for genetic influence. The physiological recordings in general showed small intrapair differences. However, during the initial discussion about how the difference arose in piano practice during childhood, the nonplaying twin used more time and showed evidence of a stronger sympathetic activation than the cotwin. These findings are discussed against the background of music\'s importance in childhood.