A great country that used to be one of the big powers of Europe (Kingdom of Hungary then Austro-Hungarian Monarchy) then after the WWI the French et al decided to strip 2/3rd of its Hungary's mainland and half the population away overnight (Treaty of Trianon), creating bunch of never-existed surrounding countries, throwing over the border half the Magyar (Hungarian) population of the historical empire. The French point was solely to get rid of another power center in Europe, especially one that had historically had very good relationship or more than decent with Anglo-Saxon powers.
This created a HUGE resentment in Hungary and HUGE existential FEAR in these newborn countries which still exist, even today (look at Slovakia!)
During the WWII Hitler used this resentment to secure Hungarian support and Hungary got some of his territories back. At the end of the war Hungary couldn't pull a Romania - switching side at the very last moment, right before the end - so couldn't secure any of these territories and was forced to give them up.
For their part CS, based on the flat-out racist, disgusting Benes decrees that are STILL LAWS IN BOTH CZECH AND SLOVAKIA, deported some 2-3 MILLION people, mostly Germans and Hungarians and confiscated their property, which they have NEVER returned or paid for until today - in fact thee laws are still in effect (of course they are when both Brits and USA agreed of the deportations back then.)
In the next 40-50 years all the surrounding countries were shit poor compared to Hungary, they all used to come to Hungary, to sell all their cheap-@ss, useful or useless crap and buy FOOD which they simply did not have enough in their countries (especially Romanians, they suffered from STARVATION for DECADES) and when they went home the food they bought here they kept chasing their Hungarian minorities hoping to turn them into Romanians/Slovaks/etc.
After the 1990 Hungary alone took HALF the total Western capital influx which further aggravated the inferiority complex of these pretty young, rootless surrounding countries.
As a result of their serious inferiority complex and the pressing knowledge of their illegally gained historic Hungarian territories some of these countries, especially Slovakia and Romania countinue to fear a possible rise of Hungary, they still abuse their remaining Magyar (Hungarian) minority, even under EU laws etc - hence these idiotic, stupid, lame, semi-literate comments about Hungary.
Nowadays Hungary is struggling with several ballast of the past, most of them all come from the single fact that in return for the "plush revolution" it never really got rid of its Communist politician heritage (most became either Socialist or right-wing nationalist @ssholes) and its entire politcal elite has been totally corrupted during the past ~20 years (since 1990, the first free elections since November of 1945.)
Ukraine is so far the best neighbor of Hungary, despite she retained Karpatalja (Munkacs area, also lost in Trianon), despite the pro-Hungary majority in the aftermath following the collapse of the Soviet Union.
Beyond all these hateful, Slavic countries the only country the non-Slavic Hungary was always able to count on and vica versa is Poland - they are true friends of Hungary (we even shared a king at one point in history.) Most likely you won't see any idiotic comment from Poles here and vica versa, we don't post any retarded jokes about them either.
This latter fact alone clearly shows that despite such neighboring claims we have zero problem with Slavs or anyone else - in fact we don't even care about most of the lost territories by now because it's a lot easier to re-colonize them with economical power (it's not an accident smarter ones supported their EU membership: it's about free movement and cultural support for our diaspora!)
Ceausescu leveled THOUSANDS of tiny native Hungarian villages in Transylvania.
Slovakia's shameful Benes laws are still so much alive that BOTH OF THESE NEVER-EXISTED, BUILT-ON-STOLEN-LANDS countries (Czechs and Slovaks, LOL) still REFUSE to revoke the Benes decrees, even despite Hungary and Germany common diplomatic pressure - anti-Hungairan laws are in effect, ultra-right-wing nationalist parties are not only in their Parliament but IN THE GOVERNING COALITION, openly calling for a war on Hungary, sending tanks to Budapest (like if this 3-4M newborn country would stand a chance to attack anyone, ROFLMAO!)
Since the beginning of Yugoslavian War local Magyar (Hungarian) minorities are regularly attacked in Ujvidek (a.k.a. Novi Sad) for speaking their native language, even today...