I wonder if there are any studies that look at how hard it is to permanently readjust muscle memory as you age.
Would I ever (at 31) ever achieve the same fluency with emacs if I switched cold-turkey today as I've developed with vim in my teens and twenties? What about in my fifties?
I'm 33, switched to emacs the end of the last year, still find the way that vim edit files better, but the ecosystem around emacs has a ton of niceties, so for me the solution was to install evil-mode and configure it to work as close as possible to my vim configuration, but in the end I decided to left some things the emacs way.
Now I sometimes find myself using some of the emacs shortcuts when editing files with vim...