Originally Posted by ltc444
As Murphy said: No plan survives the first contact intact.
Murphy may have codified the general principle of things that go wrong, but the author of the particular quote is (was) Field Marshall Helmuth von Moltke (the Elder).
Chance favors only the prepared mind. (Louis Pasteur) Good to keep in mind when you are preparing your defensive plan.
When the everyone around you is losing their heads, having a plan that was good before first contact is far superior to having none. Prepare, train, perform.