Ancient history.
The relationship between Memory and Pain on a neurological level.
Neolithic and Beaker cultures of Ireland. Specifically the neolithic monolith building era and the interaction between the Beaker and indigenous peoples.
I imagine this would entail considerable time prowling around Ireland and searching for clues in folk-culture (aka - drinking at the pub).
The passage tombs … oh, to have the knowledge and opportunity to really investigate Knowth. I’d give your left arm for that alone.
Crap, missed the edit window.
I just read 2001 and 2010 recently, so when I said “monolith” above, I actually meant “megalith” :smack:
Big band music. So little of it is heard today, just the same 25 hit tunes over and over. People honestly have no freaking idea how good some of it was - indeed, is.
Battleship construction, operation, and design.
Neuropsychology.
It’s endlessly fascinating, and has a ton of potential useful application.
I would follow Howard Hughes seminal work and become an expert on bra design with a view to excellent cleavage.
Or just a view of excellent cleavage…
It’s a toss-up between ancient and medieval armed combat and smithing. I have a decent amount of knowledge on the first subject, including some very limited but fun time fighting in armor, but smithing is something that book knowledge can only take so far, and it’s much harder to find facilities and/or a teacher to learn with.
Either Hip Hop Dance Styles through the past 4 decades, or British Colonial History, or sailing.
Languages.
I would devote my time to studying as many languages as is humanly possible to become fluent in. All of them, maybe? Sigh… I don’t think I could live that long. I’d love to be able to travel and communicate with anyone in the whole world. And to become truly fluent in each one, I’d need to devote a decent amount of time living in each area…
Yeah, I’d have to outlive Methuselah.
Cooking chemistry
Tsuba of the Middle Edo period, with a particular emphasis on inlay techniques.
I would like to become an expert in comic books, particularly superhero comics, and their history and impact on our media and culture. (My particular odd emphasis would be “knockout/capture scenes involving superheroines”, since that is my fetish – actually, come to think of it, I probably already am one of the top ten experts in this field! Ha!)
My second choice would be expert knowledge of the “weird tale” in fiction (particularly the “pulps”), with an emphasis on Lovecraft (of course!) and his circle.