I think I'm not so much a history nerd as a roleplay nerd. What that means is that I tend to make historical horror or historical urban fantasy roleplay characters with relatively little preliminary knowledge (beyond skimming through a few wikipedia articles) then research and tweak them as I go along and learn more of the topic at hand. For the duration of that roleplay the culture and time period of that particular character becomes the most best interesting thing I've ever read. I wish I'd known that lifehack in school, would've made 19th-20th century history classes much more fun.
I've got two characters from the 1940s (late 1945 and 1947 respectively). They're actually getting to be quite old and unused by now so I don't share them around as much as I did once upon a time.
Julia Wright/Henry Newman (colloquially H/J) - A former WW II spy for Great Britain who gets appointed to study why England's got so many cases of demonic possession right after the War is over. I, too, think Weimar Germany's queer history is really fascinating and so is England's, though I couldn't really bring those elements into the roleplay on account of it becoming more fantasy than history not too long after it's inception. Once my OC-obsession around hir died down I started feeling that s/he just...had way too much going on and I saw I'd written an ungodly novel on hir page, but as it's a bit of a memorial page for hir then I don't have the heart to tidy it up. S/He was sort of built around a desire to have a character who could effortlessly switch between genders and personas with everything else to try and facilitate that aspect. I think s/he probably trained with SOE as well, alas I only learned of SOE's existence and training regimen after that particular OC had already died.
Christine Anderson - Second character for that roleplay after H/J succumbed to a werewolf bite. She also has some historical inconsistencies, such as the fact that I realized way too long that shortages and import restrictions in the UK didn't magically disappear with the end of the war. That said she was a really fun motivator to dig into civilian life during WW II, journalistic tactics and - most of all - the state of paranormal research and debunking.
It's not strictly what this thread's about, but right at this moment I'm more into the 1860s due to being in a historical horror roleplaying server that takes place within that time period. So for one character I'm learning about Polish partition and 19th century medicine, for another character I'm learning about the art scene of 1860s London and as I'm trying to write a mystery of my own for that server I've also brushed up on all the things I studied in 8th grade history class about my own country. And I've fallen down the rabbit hole that is 19th century fakelore and pseudomythology. I think I find history interesting, I just need that little bush to really get into it. And it's the kind of thing that gets the more interesting the more you know about it - it helps weave seemingly unconnected events into a well-integrated fabric.