Having spent 90% of my career in either the military or corporate, two areas where decisions are made “on the fly”. Many, many times changed all kinds of routings. My prize was a change in destination, airborne, from home station to Brussels, BE. Everything had been planned for Belgium where the new helicopters were destined, but we had a maintenance problem during pre-flight. TACC decided to send to either Dover or Westover for the work. Magically, C-5 fixed itself airborne, asked Indy Center for Brussels. The controller cleared us to BRU and said, “hope it works”. Sure enough, Gander had the oceanic clearance.
Another time, we changed destination on the East Coast so many times, Washington Center gave up and said, “do what you want MAC, and keep us informed”. ORIs are fun, if you’re flying.