If you have been inspired to become a ninja after watching them in some movie or some spy thriller, then there are some things that need to be unlearned, before I talk about becoming one in the true sense.
Being one is not about moving around in black costumes stealthily, on killing missions. It is a way of life, based on the Nunjitsu philosophy.
The ninjas were a creed of warriors that originated in 14th century Japan, out of a need for espionage and special offensive tactics. They were specially selected warriors from among the ranks of the Japanese army, which specialized in pulling off jobs that went far beyond the realm of the possible.
These warriors knew no limits, when it came to accomplishing jobs and they could do things that did not fall in the ethical rules of the Samurai even. For those who came in late, Samurais were Japanese warriors with their own code of conduct called the Bushido. Ninjas were expert assassins, used by the state for guerrilla warfare and specialist tasks. They were the medieval Japanese equivalent of what are today's commandos. These warriors of old were trained like the commandos to survive in any kind of terrain and were masters of martial arts.
How to Become One
The relevance of the ninja way of life in today's context has to change, when one thinks of adopting it. The value system of these warriors, which included principles of concentration, endurance, strength, self control, and achieving the peak of one's mental and physical abilities, is something that one can adopt, to lead a fuller and more satisfying life.
If you want to know how to become one, then be prepared to subject yourself to a series of never ending challenges, aimed at conquering fear. Learn any one of the martial arts styles for a start.
The deadliest style of martial arts is any one which you can learn to the point of being a master. Master unarmed combat for self defense and offense, if need be. Read as much as you can about the Nunjitsu philosophy.
Develop your body through regular exercise and become a part of adventure sports activities like rock climbing, river rafting, etc. It is all about subjecting yourself to the elements and testing your mettle.
Learn 'Parkour' and practice it. For those who came in late, this is a game of overcoming every type of obstacle that comes in your way. Join a Parkour club if any, in your town. It will give you a taste of what those ancient ninjas did for a living.
Know the beauty of silence and solitude. Practice self control and learn to be patient. Learn to meditate and exercise your mind with games like chess and mathematical problems. In short, I have redefined the concept of becoming a ninja as a process of testing your limits in every way and every aspect.
It is all about reaching the peak levels of consciousness, and being aware of one's own nature and things around us. It takes years of practice, training and discipline to become a true ninja warrior. It is not about annihilating enemies physically, but about combating and destroying the inner demons of fear.