One of the things that I have yet to see a time management course really handle in a useful way is the idea of "discontinuous change". A discontinuity is simply where the world takes a sharp turn. ("Discontinuity" is a math term for a function that isn't smooth - that has a "kink" or a "gap" in it, so to speak).
When talking about life, a discontinuous change is one that changes the plan/priorities/goals in a radical way. It's a situation where you're going along, and suddenly...
... the world changes and what you thought was going to happen, well... isn't.
I know a few people who are dealing with discontinuous change, and it's interesting to watch. It is in the moments of discontinuous change where you see people's coping mechanisms clearly. Some people get aggressive and try to shape the new world, while others go into a mode of what can almost be described as apathy... they sit and do nothing until the world rights itself. Still others continue on with "business as usual" as if the discontinuity wasn't happening.
What I find most interesting is that very few of the books on time management and priority management have really tackled the idea of discontinuities - the closest I've seen is some vague discussion of the type of discontinuity presented by an internal realization of being unaligned (i.e. the "midlife crisis").
So, what really is the key to surviving the discontinuous event?
In my experience (and I'm going through a discontinuity now, as Bill describes in his blog) is to attempt to remain focused on your real long-term vision and mission. When the rug gets pulled out from under you, what best is able to orient you is that understanding of your vision and mission - it is that understanding that can give you the ability to sit on the sidelines and know when opportunity is showing up.
This is sometimes incredibly hard to do, especially in the really serious discontinuities (e.g. death of a long-time spouse, serious illness), but the key is to know your purpose in life and allow that to re-orient you. This is one of the reasons that religion is so helpful in times of great discontinuity - for many people out there, their religion provides purpose (i.e. "serve God's will by doing X and Y...") in life that allows them to reorient.
Much like Col. Boyd said, the ability to orient most quickly provides the best ability to survive in battle. In times of discontinuity, it is that understanding of purpose that allows a quick reorientation and recovery.