Concentration is personal power.
Being able to concentrate opens the doors to the mind in ways that are extremely powerful.

One of your biggest assets is your power to concentrate. Not only does it make you a better thinker, it also gives you access to incredible powers of the mind.
According to Indian mythology, concentration is the ability to focus on a single thing and merge with it in your mind.
As you do so, you accumulate energy in what you concentrate on, and it becomes a power field in its own right. You can now channel this power to other places.