Our-modern-selves-popped-back-in-time-or-into-fantasy-worlds is a staple of gaming. I was once asked how I’d handle being popped back into 1915 Germany.
My answer? Get to the United States as soon as humanly possible, where I would die a very, very rich man.
I'd start with placing bets on the outcomes of the next couple World Series (I know the Red Sox win both), parlay that into the 1916 presidential election, change my investments into war industries in time for April 1917, then bet on the 1917 and 1918 World Series (the White Sox and Red Sox win, respectively) before placing a bet on the date of the Armistice. In the meantime, I win bets on the outcome of the National Hockey Association season in 1915 (Ottawa Senators), 1916 and 1917 (Montreal Canadiens), while the Toronto Blueshirts win the first NHL season in 1918. I get the hell out of Dodge and onto a remote Vermont farm in time for the 1919 influenza pandemic, win bets on the next few presidential elections, ride RCA in the stock market until my eyeballs fall out, and cash into gold holdings in early September, 1929. Yes, I know the Great Crash was at the end of October, but there was some yoyoing before it, and I don’t want to be caught leaning the wrong way.
[Good call, just having looked it up. The highwater mark of the NYSE was September 3rd, and the market started declining after, and cratering on the 18th.]
I promptly shift that gold to a secure trust based out of the Bank of Montreal (which off the top of my head I know survives to the present day) by no later than the summer of 1932: I forget exactly when Roosevelt made private holdings of gold illegal, but it can’t have been long after he was elected, so getting that gold to Canada (which never banned private ownership of gold) is crucial. Off to the races.
This is all information I know off the top of my head, and that might be critical: I'm minded of how Heinlein depicted time traveler Lazarus Long, who studied assiduously the time of his far-off youth -- the Kansas City and America of the time between the end of WWI and the beginning of the Depression -- preparatory to a long visit, only to be wrongfooted when he overshot and landed in 1916 in the run up to the United States' entry into the war.
What's that you say? Not very heroic? I'm supposed to hang AROUND Germany? Adventuring?? (shudders) Even if we were, say, Americans, and therefore from a "neutral" country, it would be difficult to pass for Americans:
* Even if we were 1910s antiquarians, we wouldn't have a smooth, natural command of then-prevalent idiom.
* Our knowledge of current events would be scanty at best - quick, without looking it up, what were the top local issues in your city and state in February 1915? Who was your governor? Did the community in which you live even exist?
* Our knowledge of pop culture would be worse; how many of us could name, let alone hum, five popular songs from the 1910s? Who were the stars of your local baseball team? What’s playing at the local picture palace? Fair enough, a couple of you might recall that Birth Of A Nation, the most famous film of the silent era, was released in 1915. Can you name any other film from 1915? (No surprise if you can’t: Birth Of A Nation outgrossed the next ten films combined, tenfold.)
* Most damning, our knowledge of current technology is scanty. Off the top of your heads - by way of example - how many of you know how to start a 1915 model automobile? This is an interesting scene in Heinlein's book about Lazarus Long going to the past and needing to start a car, with all the switches and settings one had to work in 1916. I'm minded of my maternal grandfather -- born in 1902, three years before Heinlein -- telling me that horses and buggies were still making business deliveries well into his adulthood in our mutual hometown, Boston's immediate southern suburb ... and his wonder at having lived to see moon landings, supersonic transcontinental travel and computers.
(Or even pretty low-tech technology. Long years ago, before Yankee magazine turned into a travelogue for rich people, its letter column encouraged entries -- and featured at least one a column, with accompanying illos -- based around "What's this weird farm implement I found in the barn?" And the editor would reply, "Yeah, that's a potato dibber, and this is what it was for, pre-mechanization.")
But hey, look, what if I succeeded in convincing the locals that I was, truly, an Ami? Great, now if I'm foolish enough to stick around for too long, I get interned when the United States declares war on the German Empire ...