When she entered, Celestia looked up and beamed at Twilight, then got back to her discussion.  As impatient as Twilight was, she couldn’t help but listen to the complicated workings of the castle.  It directly employed hundreds of service ponies, three companies of the Royal Guard, and had its own post office; the Castellan and Bailiff were responsible for keeping them all in order and performing their tasks.  She had once drawn out a chart of who was responsible for what, after listening in on a similar briefing.  It had taken her days, and two trips to the library for additional research, and she had been chagrined when the Castellan had, with just a casual glance at her chart, corrected dozens of mistakes, and written in an entire branch, under the watchful eye of the High Marshal, of which she had been completely unaware.