However, if you've ever had someone apologise and then add "...but I didn't mean to..." or "...I just had to..." or "I was just trying to..." then you know how much the why can diminish or even negate the power of an apology. Too much focus on the why can result in excusing extremely hurtful words or actions.
Understanding the why can be a key to unlocking conflict. If someone's actions baffle me or have caused harm, then understanding why can help me to have empathy. For example, in mediation we ask about needs and interests to help establish the landscape of a conflict. In a sense, we are curious about the why in order to make sense of the what. What were they seeking to achieve? What did they want from that situation? What response did they expect?
Over the years, I've come across many examples of how understanding why is also a huge trap. We all want to feel that our behaviour is reasonable and our words are clear. Most people act "reasonably" most of the time, if we view their behaviour in the context of their why. The problem is when reasonable for one person is unreasonable for someone else.
The trap is when one person's need to explain why a behaviour was reasonable overpowers another's experience of the consequences or impact.
Whenever we find ourselves on either side of that conversation, we could do well to listen to the other person's why but not get too attached to our own.