In his 1908 book Scouting for Boys (the earliest Scout Handbook), Lieutenant General Robert Baden-Powell gave the definition for "Be Prepared." He said:
"BE PREPARED, which means, you are always in a state of readiness in mind and body to do your DUTY; Be Prepared in Mind by having disciplined yourself to be obedient to every order, and also by having thought out beforehand any accident or situation that might occur, so that you know the right thing to do at the right moment, and are willing to do it. Be Prepared in Body by making yourself strong and active and able to do the right thing at the right moment, and do it."
Later on someone asked him, "prepared for what?" He famously responded, "why, for any old thing!"
Being Prepared is a mindset. It is hoping for the best but being prepared to handle the worst. For me personally, it was the forethought to pack a wool sweater when traveling to tropical West Africa, even though the temperature was never going to drop below 80 degrees. I sure was glad to have had that sweater when a mystery illness gave me the shivers. Once again, Being Prepared and following the Troop Packing List meant that I had a jacket in July at summer camp two years ago, and let me tell you, we needed jackets two evenings because it was cold in the mountains.
Your training teaches you to Be Prepared. Don't get caught by surprise. Don't let the wish for the best conditions cause you to be ill-prepared for the worst. Prepared for what? Why, for any old thing!
Be Prepared!