I've been waiting a LONG time to post this discussion between Celestia and Berry Punch. It is an author favourite, but I don't expect too many people see it as anything special, but buried in the discussion is the entire how and why for Celestia and Luna's different approach to ruling. Celestia is a watcher, and Luna is more prone to bonk little heads if they rear up. Somepony has to scare them back into the nest. And protect them from typos.