Center ?

In many ways we learn to walk straight to bend with your torso upright and so on. Some arts teach you to move from the center line which is the line from the chin to your groin but rarely the true center is discussed or harnessed.
Start working any drill with pairs wrestling hitting or anything else and a third partner walking around and pushing around the people who are paying attention just to the person they are in contact with. Change roles and watch the difference in movement and in sight coverage of the different working people and keep breathing.
Repeat the drill and have the person walking around hold his breath as he looks outside while the breath holding is forcing his or her attention inward. During this drill pay attention to your interpretation of other people and see how things change as your inner tension grows.
Now have two or three on one pushing and pulling the one and without warning change the person you are pushing again and again. The moment to pay attention to is the switch as you are looking for your place in the drill instead of just moving.
The real center is how you pay attention to yourself and others. Too much attention to others will take your life away and the same is for too much attention to just yourself. There is a saying Complete abstinence is easier than perfect moderation. by Saint Augustine. Mind how you take and how you give until they are the same for you and then you will be free.