This is an old proverb from the 17th century and it's not nationalistic in the modern sense and it's not in use in Hungary.
It reflected the main goal of the Hungarian nobles of the 17th and 18th century: to uphold the status quo, no matter what happens abroad.
After both the Treaty of Vienna in 1606 and Rakóczi's War of Independence in 1711 the Hungarian nobility reached a compromise with the Royal Court in Vienna (In Hungary the Habsburgs ruled as the King of Hungary as Hungary was not part of the HRE, hence the Royal title). Those compromises meant that the King respected the rights of the Hungarian nation (which meant only the nobility, so a Hungarian peasant was not part of the Hungarian nation back then, while an ethnically Slovak nobleman of the Hungarian Kingdom was considered Hungarian) and the autonomy of the counties, guaranteed the religious freedom and respected the unwritten constitution (Golden Bull of 1222, Tripartitum etc).
Between 1606 and 1686 and from 1711 to the 1830s the Royal court respected these agreements and the Hungarian nobility "withdraw" to the counties. They sent their representatives to the feudal parliaments, voted the military budgets, etc. but otherwise they acted almost like the Hobbits in LOTR. If they had a foreigner visitor, that was a rarity and they wasn't interested in foreign ideas, like Enlightment and such.
In the 18th century the counties of Hungary was acted almost like 50+ small, separate countries (for example they stopped chasing bandits on the county borders) and they really didn't care what happens elsewhere in the country. And if that elsewhere was not even in the country...
This noble paradise was ended when the French Army beat the "Hungarian Insurgent Nobles" (that meant the rural landlords on horses as they tried to defeat the professional army of Bonaparte) badly in the Battle of Győr in 1809. That defeat, which forced King Francis to sign the Treaty of Schönbrunn with Napoleon showed that the Hungarian nobility couldn't defend the country. When the war ended in 1815, the grain prices began to decline, which destroyed the financial basis of this golden life. In 1825 the young, romantic aristocrat, Count István Széchenyi started to ask questions about the state of Hungary and liberalism became the new mainstream ideology of the nobility and the Hungarian elite until 1918.