This happened to me early on in programming career. Coming out university I had a highly customized emacs environment, that I regularly tweaked. But then on my first job, while I could use emacs on my workstation, our production systems were all Solaris were I could only use vi (not VIM, vi). The cognitive load between them killed me and I retrained myself on vi. Today I use vim, but really only change a few things like the theme.