Culture Shock

You're taught to expect this when moving to a new post. At some point all the excitement of the shiny new experience wears off and you wonder why your doing this at all. How long it lasts, how hard it hits, and how soon into your tour all varies. The same happens with the career as a whole. At some point you get very introspective rather than just bouncing along enjoying it all. They also teach you that it always passes as you reconcile reality with your expectations.