Seen from a childs view. Are German/Austrian children taught (both in school and by their parents/adults) that they were on the "wrong" side, as you will be taught in countries that belonged to the Triple Entente/neutreal (like Norway, where I live).
Is Alsache-Lorraine still a disputed territory? In the sense that German people will tell their children that it actually belongs to Germany. Same with South Tryol, is there still a vibe in the Austrian/Italian population that "they took this from us"?
Will a Belgian/French child have an attitude towards German/Austrian children if they have been taught about the war by their parents/teachers?
These are quite specific, but what is the general vibe of the populations in both sides of the war?
Alsasse-Lorainne isn't disputed anymore except by Neo nazis. The same with the Czech/ Polish parts of former Germany.
The longest running conflict born out of WW1 was South Tyrol.* In the 60ies you had several german nationalist terrorist groups who wanted South Tyrol to become part of Austria again. This was only settled very late, with the autonomy of South Tyrol and several special legislations regarding its status.
Today, becoming part of Austria is a fringe view within South Tyrol. But if you'd ask people in Austria you'd still often get the answer that it is rightfully "their" territory. So yes, there still exists some revanchist sentiment within Austria.
*edit: Reading the comments it came to my mind that I omitted the Ottoman/ Armenian/ Greek/ Turk clusterfuck who still holds power today.
German children are taught that the political climate at the time fueled a conflict that eventually escalated, that not one but several countries are to blame for that and that german attitude (often shown in the form of Kaiser Willhelm II) at the time is among the main reasons for the escalation. Its really not a big subject though and just a quick stepping stone leading up to WW2 (with a brief halt in the Weimar Republic).
For Germany WW1 is not "the war". If german people talk about "the war", they always refer to WW2. There is little to no bad blood regarding just about anything that happend before WW2 in german society. Consequently, Alsace-Lorraine is not considered german or even brought up as an issue in any way, shape or form. Not even right wing fringe groups bother to
I have never encountered "attitudes" regarding WW1 from any of our european neighbours, except for football banter from the british of course. Quite the opposite even, for the German/French relationship WW1 could be considered some absurd kind of bonding experience. Again, a good symbol for that might be the famous President Mitterrand/Chancellor Kohl picture taken in Verdun.
Among Hungarian nationalists, there's a sense that the Treaty of Trianon was unjust because of how many parts of "Hungary" (areas populated with ethnic Hungarians) were "abandoned" in other countries, Romania especially (30% of ethnic Hungarians were left out of the new Hungarian state). Look at this Trianon memorial, which depicts the treaty as a guillitine chopping up Hungary, or this one mourning the loss of much of its "traditional borders" (it depicts modern Hungary within the borders of the Hungarian portion of Austro-Hungary). Obviously, Romania, Serbia, and Slovakia viewed the treaty as establishing their "right borders" and "national liberation". There are about 1.25 million ethnic Hungarians in Romania (about 6.5% of the total population), less than .5 million in Slovakia (about 8.5%), and .25 million in Serbia (about 3.5%). There are something like 8.5-9.5 million Hungarians in Hungary, depending on how one counts, meaning that even after decades of migration (in 1948, for example, there were 430,000 Hungarians in Serbia, making up 7.5% of the population), especially since 1989, a giant portion of Hungarian speakers are outside of their nation-state. While officially,
The systematic murder and expulsion of Ottoman Christians, commonly called the Armenian Genocide (but actually involving many other Christian groups, especially the Greeks and the Assyrians), is obviously also quite controversial. The mainstream opinion within Turkey and Azerbaijan is that there was no genocide, and in both school systems it's taught that ethnic Turks were the real victims of ethnic violence (which of course they were, though on a smaller scale). Obviously, this is not how this period is remembered or taught in much of the rest of the world. Within Armenian nationalist fringe groups, there's a sense that the Armenian traditional Armenian heartland around Mt Ararat and Lake Van, maybe even all of Wilsonian Armenia, "should be" part of the modern state of Armenian. There is also controversy around the post-WWI decision not to allow the creation of a Kurdish state, see here. Obviously, the wartime Balfour Declaration, which paved the way for a Jewish state in Palestian, also has had some controversial repercussions up to the present.
For the British, and by extension for much of the English speaking world, WWI is seen as some kind of national tragedy, an unsurpassed trauma, and an irrecoverable disaster.
The blame for most of this is popularly laid at the feet of the aristocracy and the generals - the latter being (commonly but falsely) perceived as the "donkeys" whose cruel and obstinate stupidity lead to the deaths of hundreds of thousands of men as they walked into machine guns.
Correlli Barnett touched on this in The Collapse of British Power where he refers to this perception as forming the core of what he calls "The Great British Excuse" for a collapse in British national vitality. The perception being that WWI was so traumatic and catastrophic that it permanently crippled the nation.
Of course, relatively speaking the British did not suffer disproportionately in WWI and as John Terraine points out, actually emerged from WWI with a fairly strong hand of cards:
she possessed incomparably the most powerful Navy in the world, and her most serious naval rival had been eliminated;
she possessed the largest Merchant Marine in the world;
she possessed the largest Air Force in the world;
she had an Army of over 3 1/2 million men, including the most effective contingent of the victorious Allied forces on the main front;
her industries - some of which had been decidedly backward or flagging in 1914 - had received great stimulus; important new industries had been created (for example, chemicals, dyestuffs, optical glass and instruments, non-ferrous metal refineries, aircraft and aero-engines);
there was full employment - indeed, a labour shortage; and over one million square miles were in process of being added to Britain's overseas possessions and dependencies.
It can indeed be argued that the British perception of WWI is best seen through the filter of an island nation who for centuries past had contributed only small contingents of volunteer armies (composed of an illiterate underclass lead by second sons of the aristocracy - both expendable) to continental and colonial wars.
The shock of WWI was therefore that the British public - the educated literate middle class British public - had first hand experience of war for the first time - and they found the experience traumatic.
TL;DR - The British regard the war an event that permanently crippled the nation, and it was entirely the fault of their own ruling class - The British generals being perceived as far bigger villains than the Kaiser.
An additional related question. One of the things that really surprised me reading The Sleepwalkers was that Serbian intelligence really was involved with the assassins who killed the archduke. Is that something you could typically learn about in school in Europe?
