Okay, gotta ask, which idea was as crazy (not that I don’t believe you, but I love crazy ideas).
I’m glad somebody finally asked.
The idea was that all the electrons and positrons in the Universe are only one particle, since the positron is the same as an electron going backwards in time.
https://en.wikipedia.org/wiki/One-electron_universe
I like Feynman’s quote in the article from his Nobel speech:
I did not take the idea that all the electrons were the same one from [Wheeler] as seriously as I took the observation that positrons could simply be represented as electrons going from the future to the past in a back section of their world lines. That, I stole![