One of my favorite quotes:
"Plans are worthless, but planning is everything."
-Dwight D. Eisenhower (Supreme Allied Commander for the Normandy invasion)

Emergencies will will rarely if ever happen exactly as you expect (that's in the nature of emergencies), so things will not work out exactly as you planned. However, you are still much better off by having done the planning. You will have evaluated your assets, strengths, and weaknesses. Presumably you will have tried to compensate for areas where you are weak.

It is always easier to modify an existing plan to fit the circumstances, rather than to start from scratch under extreme duress.