Living so close with destruction and death, Apostolidis stated that he swore to himself not to shoot a single bullet, and to record what he was going through for two and a half years in Grammos, Vitsi and during the cleansing operations of Roumeli and the Peloponnese.
In 1950 he completed his studies and started teaching Ancient and Modern Greek, History and Latin in private high schools of Athens.
He collaborated with several newspapers and periodicals of Athens as an editor of Eleutheria, Niki, Eikones, Gnoseis, Neoteron Lexicon Iliou, Aneksartitos Typos and other publications, as well as book critic in Grammata, Fititiki Foni, Deltion tou Vivliou, Kiklos, Kochlias, Nea Estia, Neoi Rithmoi, Nees Ikones, Ethnos, Ethnikos Kirikas, Epoptia and Nea Koinoniologia.
In 1966 Apostolidis started publishing in Modern Greek serialised fragments from the diary of Ioannis Metaxas accompanied with his own sarcastic commentary.
The trial took place after the Coup of 21 April 1967, and the establishment of military dictatorship, and so the circulation of Modern Greek stopped, which until then had published five articles related to the first two volumes of Metaxas's diary.
The crowd fought with parliament members of the center, an act for which Apostolidis was arrested and sentenced to two and a half years in prison, serving three months in total.
During the dictatorship in Greece, in 1969, Colonel Georgios Papadopoulos imposed issue of the Short stories Anthology of Heracles N. Apostolidis in the Athenian Press, under the condition of not being censored.
After the end of the dictatorship, until 1979, Apostolidis continued writing critiques in the quarterly periodical Tetramina and published several of his works.