Change is reality of our existence and attempts to resist change are always unsuccessful and produce great suffering. Learning to relax makes us better able to flow with change. Since every situation is different, we concentrate on principles rather than techniques.
When we are in a circumstance that is giving us great discomfort our tendency is to resist which only serves to further increase our suffering. Often when people begin to practice T'ai chi or are doing their first form after a day of stress, the slowness of the movement is difficult and even uncomfortable, particularly if you resist or fight that slowness. In daily life this is also what happens to many people who find themselves in slow traffic resulting in the road rage phenomenon. In push hands, it is when you resist a push instead of learning to relax and receive it with skill or when you try to force a change to occur.
In most of these cases the source of our discomfort cannot be changed, but what we can work with is our resistance. This can be achieved by increased awareness or presence of mind. In T'ai Chi we call this listening energy: a way to relax and let go of the resistance. As our awareness of the present moment increases, we can reduce or eliminate our resistance.
In situations that we perceive to be pleasurable, our fulfillment is often canceled by the tendency to grasp and futilely demand that our pleasure not go away. People who have developed their form over some months and years and who reach a place where it is feeling good will inevitably be frustrated when it starts to feel not-so-good without realizing that this is a natural process of growth and should be welcomed. In push hands it can happen when you feel a connection to someone's center, but that connection disappears before you've had a chance to push so, in frustration, you try to make it happen anyway.
Both grasping and resistance are an unwillingness to change that can be overcome by increased awareness and presence of mind or listening.
Some changes are perceived as pleasurable and some as painful. Some tend to be resisted and some grasped. But in both cases there is an unwillingness to let go. This is the skill we want to develop through our T'ai Chi practice. The form and especially push hands give us numerous opportunities to learn about the nature of change.