Why vim was opening markdown files slowly.

A few months back I upgraded my vim configuration to use pathogen for managing my vim plugins. Since adding plugins was now a doddle I found a few lists of “super-duper useful vim plugins you must have” and just installed them blindly. Along the way I also configured how various plugins and the like were configured. This included a one-line change to associate .md files with markdown (by default they associate Modula-2 which I haven’t written code in for 20+ years).