Asking "Why" Can Be A Deflection
We have a deep tendency to want to know "why". It's so understandable. There are times where if we understand why, it can relieve some of the pain. Going into the mind to discuss or wonder about the "why" can actually be less painful than just feeling the experience. So, it's understandable that our mind would try to find a way out.
But, wanting to know why is often an attempt to deflect what is being felt. Mindfulness of the body is just knowing what is happening physically, energetically, emotionally on a purely sensational level. Explore what happens if you allow the energy and sensations to flow and move in the body, even if it is uncomfortable. When you notice the mind searching for why, is that relieving? Does it offer peace? Or is it more agitating? Is it an escape?
See if there is a natural resolution of the energetic/sensational movement by just offering a gentle, tender, receptive, and consistent awareness. If you sit with something and it reveals a complete cycle, let the fact that it resolved register in your body. Meaning, take note about what allowed resolution. Then your heart-mind will have more confidence to not interfere next time.
Sometimes a why is revealed, but often something just completes and it remains a mystery. It might be less psychologically gratifying, but when a process arises and passes in this way, its pattern is actually diminished at a deeper level.