In the mid-1980s, Dario Donatelli participated in a laboratory study of the effects of around 800 h of practice on digit-span and increased his digit-span from 8 to 104 digits. This study assessed changes in the structure of his memory skill after around 30 years of essentially no practice on the digit-span task. On the first day of testing, his estimated span was only 10 digits, but over the following 3 days of testing it increased to 19 digits. Further analyses (...) of his recall performance and verbal reports identified which mechanisms of the original memory skill he could retrieve or reacquire over the 3 days of practice. We discuss theoretical implications for the retention of skilled memory performance, the effects of age-related changes in memory on it, and for the future study of the effects of disuse on exceptional performance and complex skill. (shrink)