"People poisoned alcohol during prohibition."
Once you get to that point, you realize that the lessons of history apply all around you. Basically, people are still people. And what happened before, is bound -- history demonstrates, very likely to -- happen again.
You learn to view everything with a critical eye.
I guess I can't avoid the meme: "Because people."
OTOH, this also means that the beauty and awe found in history is also to be found around you, every day. You don't have to leave your time and place to... "live in interesting times."
So, have a good Sunday (today)! :-)