Korea's nationalism is still strong today, and some extreme nationalists have pretty far-fetched theories about the origins and forgotten history of the Korean people. The theories exposed below are in no way representative of the general opinion of Koreans on their history. They are the work of a minority of what could be taken for Internet trolls, if only they didn't seem so serious about their claims.
I've always been fascinated by the creativity and poetry of nationalist movements. Some nationalist movements managed to rewrite or just completely invent mythologies, traditions and tales that are now fully part of their nation's culture. Korean nationalists of the 19th century did an incredible job of interpreting and arranging the country's history and its creation myths, something I hope to be able to write on in the near future.