Shaolin kung fu is not just about defending yourself against an attacker or inflicting bodily harm. Shaolin martial arts also stress discipline, respect for yourself and others, patience, and being humble even in victory. The mental training of Shaolin martial arts helps prepare the student for any events that may come. Being physically prepared for an altercation is good, but if you are not mentally prepared you will not be focused enough to use the tools that your body has. This is why Shaolin meditation is such an important part of the Shaolin martial arts training. Meditation may not be literally practicing your physical tools, but it allows your mind to make better use of those tools.
Keeping cool in a self defense situation is one of the best ways to ensure you will survive. Tough mental preparedness allows the body to be pushed beyond its physical limits. Out bodies can only do so much, but our minds allow for much greater feats. I am sure you have heard of "mind over matter" and the truth is that it works. When the Shaolin added mental training to their physical training the result was that their martial arts system obviously surpassed all others in application and practical results.
One form of Shaolin meditation is called "Chan" or "Zen". The Shaolin received the concept of Zen meditation from an Indian priest named Bodhidharma. What Bodhidharma did that was so unique was to introduce breathing patterns into the meditation. You see Bodhidharma would find that the Shaolin monks were falling asleep during their meditation, so he added the breathing exercises to help keep them focus on increase their mental development. To this day Shoalin Kung Fu practitioners still use Chan meditation and it has formed the basis of the Shaolin mental preparation and development.
The Shaolin monks would prepare their minds to withstand the most terrible conditions so that when faces with those conditions in the real world, they would be prepared instead of shocked. Knowing that you have the mental toughness and readiness instills a confidence that allows you to go into any situation ready to act without hesitating. Self doubt is the number one way to be defeated before the enemy has even thrown a punch.
Meditation also allows one to focus his inner energy into his actions. The Japanese call this Chi, and many Westerners have heard of it. The Chinese, however, call it Kiai. Kiai allows a Kung Fu student to do things their physical body alone cannot do. Developing control over your Kiai is a matter of intense mental strength and conditioning. While some people may scoff at the idea of Kiai, and it is true that it might be more of a mind over matter application than an actual force, but Chinese Kung Fu masters has demonstrated their control over their Kiai by doing physical feats that would otherwise be impossible.