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.
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.