I don't know if I'd be more scared of the flu or the approaching World War II, if I went back to 1918. I couldn't even stop it, much as I would want that, because I wouldn't have been born without it.
But if your character went back to 2020, he could have landed even earlier to perhaps prevent the pandemic - or keep Putin from starting that awful war? So many possibilities. I think I'm glad that time traveling only happens in fiction
