I grew up mostly with Turbo Pascal as my development environment. When I started to write C code in DOS, I used Turbo C briefly but for some reason I switched to the BRIEF text editor for a while.
Around 1989 my friend Max Mendizabal who used nothing but Epsilon told me "Unix is the future, if you learn Epsilon, you will be ready to switch to Emacs when the time comes".
When I eventually switched to Unix in 1992, having learned Epsilon was useful, but Emacs was too slow for quick edits. I still used Emacs for programming, but for quickly making changes to a file, I ended up learning vi.
When computers got faster, I tried to switch to Emacs for all my editing tasks, but my brain had been hardwired. I even added "alias vi=emacs" to by shell, and I would find myself typing subconsciously "/usr/bin/vi".
To this day, I use both editors interchangeably.
In any case, the above story was just an excuse to introduce VI Mode for MonoDevelop.