Kulbok attended the Nõo Gymnasium and achieved good results on national olympiads of mathematics.
By his skills, he could have qualified for the all-Union olympiad of mathematics; however, due to his displayed lack of respect for Soviet politics, he was never selected for that round.
[1] He's earned notoriety by several interesting actions, most notably by having himself pilloried for failure to derail Estonia's entry to European Union, and his declaration of revocation of his Estonian citizenship.
As of 2007, Kulbok is the only natural-born citizen of Estonia known to have voluntarily requested revocation of his citizenship without naturalising in another country.
The Supreme Court refused to consider the matter, arguing that only President of Estonia can rightfully present such a petition.