We are native Romanian and Hungarian speakers, fluent in English, and can get along with Hebrew, Italian, French and German.
We are not geniuses, just went to school, pay a bit of attention, and have some good connections. Probably also helped the fact that Transylvania is a multiethnic region, nowadays with roughly ~ 60% ethnically Romanian people, ~ 20% Hungarian (Magyar, Székely), ~ 8 German (Schwabian, Saxon, Zipser), ~10% Gypsy, and under 5% Ukrainian, Serb, and other ethnical groups.
The situation was a bit different during the 18’Th and 19’Th century, when probably it was something like: ~ 40% ethnically Romanian, ~ 25% Hungarian, ~ 15% German, ~ 10% Gypsy, ~ 5% Jew and under 5% Ukrainians, Serbs.
I can personally say, as long as I know, that I am something like 25% German, 25% Romanian, 25% Hungarian, and not sure about the rest because one of my grandpa’s was born somewhere in Galicia (present day Ukraine) and there the situation was even more complicated .