916 Days of Emacs
I've been a hardcore vi user pretty much my entire life, but I decided to force myself to spend a year using emacs a while back just to see what all the fuss was about.  When the year was over and I "allowed" myself to return to vi, it was like a huge weight lifted off my shoulders... to this day I still don't see what the hype was about.  On the plus side, though, I memorized the emacs cursor movement commands, which are (for some reason) the default cursor movement commands in most command line environments like the Postgres CLI.