ALongHardWinter in Germany that's taught at primary school (German native flora and fauna obviously, not British) as a long unit which also includes what hedgerow plants can be used for (what can be eaten, what can be made into tea and what the alleged health benefits of said tea is, also what not to touch because it's poison or might make you itchy...)
What I'm asked as a British citizen living abroad (I've taken my German citizenship test) is often about religion (people believe there are no Catholics/ no Catholic churches in the entire United Kingdom because they are aware of Henry VIII but in isolatio, and somewhat aware that Ireland is Catholic and believe that all Catholics left NI long ago).
I get asked to clarify the difference between England/ Britain / the UK.
I get asked whether there are any mountains in England.
I am expected to know everything about the monarchy.
I get asked about the school system a lot.
I get asked wtf Brexit... My answer to that is nobody knows...
I get asked random questions about how many airports London has and which is "the best"
I get asked "who was that insane British singer, you must know, name some insane British singers, I'll know when I hear the name..."
for some reason this happens fairly frequently and they often mean Janis Joplin, who was American...
But I am generally expected to have Britpop knowledge and know whether bands are British even though I'm not especially into music beyond the artists I personally like...
Those are the main things non British people seem to expect me, as a British person, to know - but not necessarily the things it's useful to know as a British person living in Britain.