Kościuszko was determined to bring his country the glory it enjoyed in the days of the Hussars and enlisted in the Polish Armed Forces hoping to join the Special Forces. After extensive medical training, he eventually passed the selections for the Jednostka Wojskowa 2305, or JW GROM. That is how he earned his nickname "Gromsko", made from the unit's name GROM, the first letter of his first name and the first two letters of his surname.