Son of a fisherman, Stefański came from a lower-class family and was mostly self-educated. He taught himself French and Latin and learned German while working as an apprentice to a German owned printer. As a teenager he took part in the November Uprising in Congress Poland against Russian rule.
References
Witold Jakóbczyk, Przetrwać na Wartą 1815-1914, Dzieje narodu i państwa polskiego, vol. III-55, Krajowa Agencja Wydawnicza, Warszawa 1989