...maybe it's hospitalists!
I must admit, "a hospitalist" is climbing on the list of Things I Might Be When I Grow Up, or Finish School, Whichever Comes First.
(and if anyone knows any other opposed ist/ism pairs, I'd love to start a collection).
(and no, suggesting something like: "environmentalists are the worst advocates for environmentalism" doesn't count).
There's much more on the web regarding hospitalists, hospitalism, as well as list of other antagonyms.