Time Away
Deployment can last for as short as several weeks to as long as a couple of years. Can you imagine spending that much time away from the people you love? Soldiers have gotten so used to it, however. In fact, they might even say that it feels like only hours have gone by instead of months.
Worst Case Scenario
Part of military training is imagining the worst possible outcome at any given moment. By doing this, soldiers will never be taken by surprise no matter how bad things might get. They will always prepare in advance in the physical and mental sense of the word!