With Celestia and Luna tired of prince Blueblood's pompous ass the two princesses decide that Bloodblue needs a personality adjustment. So with their infinite wisdom they send Blueblood to boot camp for a serious attitude adjustment.
(Author: I've never been to boot camp so if any military bronies are reading this I'll gladly take any suggestions and feed back it really doesn't matter what branch or nation you represent giving you're own personal insight would be greatly appreciated)