Dear Pam,
Just to be clear to anyone reading this, it was not a punch to the sternum. My hand was placed on her sternum and I sent energy through it into her body, while my hand remained on the sternum. The point is that when you do push hands (or punching or kicking etc.), the smaller you compress the energy, the more powerful it is "per square inch". It is the density of the power, not the total amount, that is useful. It is the same principle as women wearing high heels in airplanes. Their heels would go right through the floor because at a certain point all their weight was in the one square inch of the heel. During the 1970's, women were prohibited from wearing high heels in planes. I don't know if that rule still applies, but I don't think many women wear high heels anymore anyway.
If you compress the energy you can penetrate anyone's defenses. You train in Tai-chi and Zookinesis to have full control over the dynamics of the energy so that you compress the energy into a needle-like form and penetrate the defenses. The energy has been compressed in such a way that once it has penetrated, it immediately expands within the body cavity of the partner.
To neutralize this force you would need to perceive internal energy and be able to affect it. To perceive it requires a great quieting of the attention. The dynamics of internal energy during the "push" or strike is so fast and takes place in such a short time that your attention needs to be like the surface of a quiet lake. When the slightest breeze blows by, it is revealed by the rippling of the surface of the lake.
One part of you is still. This is yin - pure attention. Another part of you connects to the force and enters into a "playful" relationship with it. This is yang - pure creativity. The moment you can remain absolutely quiet in order to perceive and absolutely creative and connected in order to affect, then you "know" yin and yang. You know how they work together.
Yang (creativity) penetrates the incoming force before the force penetrates your body. It merges with it, taking on its shape and characteristics. By doing so, yang "feels" the intention of this force (what it intends to do, exactly what has been compressed into it). Yang can then alter this intention so that it dissipates. This all takes place in a small fraction of a second.
The reason you couldn't dissipate the force is that you haven't yet learned all this. This is why I say it takes 3 years of push hands practice just to understand what you are doing, another 2 years to be able to do push hands on the most simple level and then another five years to really develop any degree of skill. I was trying to give you a "feeling example" of a little of what there is to learn.
It is not that the material is so difficult. It is that our attention has become so deadened that we don't even have the tools to learn. And so the forms and Zookinesis begin to develop our attention - to strengthen it, to give it agility and stamina. It is only when the attention has been "honed" and developed that we can really begin to learn.
You were not in "complete resistance". You just don't yet operate on that level of energy dynamics, but every lesson you will get closer.