i think it's important to be connected to your work (when it matters, like your former boss said), but I realized that we're all just human beings, and we each have a set capacity for such things
a few people may be able to knock out life-saving operation after operation and just pound a stiff drink before going back to the OR the next day for years on end, but the rest of us can only do that sort of thing for a year or two tops before 'shutting off' (or burning out)
going back and forth between 'boring, but dependable' and 'exciting, but mercurial' seems to keep my personal trajectory interesting at least :)