I had never looked into the history of ideas leading up to general relativity. The terminology is so different than other physics and it seems to answer questions that I have never seen referenced. This article give a glimpse into the intellectual history and why it came to be. Though I found the end of the article a little unclear.
There's a really lovely Dover book which collects some of the source papers read by Einstein's group.
It's not the article that's unclear - it's the current state of physics.
TLDR; A time traveller, named Besso, came back to push Einstein to formulate his theory General Relativity earlier than he would have done on his own. This accelerated the technological growth of humanity over the next two centuries to such a degree that they were ready for the alien invasion in the year 2122.
This is exactly what I got out of it as well!
The coin example is not right. A rolled sheet of paper still has curvature 0 (which is the reason why you can easily roll it up).