In 1904, his father moved to Berlin, bringing Mateiu with him—in hopes that he could be persuaded to study law at the Frederick William University—, but Mateiu spent his time reading and exploring the Imperial German capital. He would later refer to this period using a French term, "l'école buissonière" ("the vagrant school"), and stressed that " was of great use to me". Ecaterina Caragiale indicated that one of her brother's favorite pastimes was "admiring the secular trees in the Tiergarten", and he is also known to have spent entire days at the National Gallery, especially fond of paintings by Jacob Isaakszoon van Ruisdael. Dissatisfied with Mateiu's attitude, Ion Luca sent him back to Romania in 1905, where he enrolled at the University of Bucharest Law School, but quit one year later. For a short while, Caragiale-father even entrusted Ștefănescu-Delavrancea with supervizing his estranged son.