If we need to prove we are powerful, it is safe to assume that we are compensating for feeling powerless in some way.
There is power in conscious vulnerability. We are so confident in our power that there is nothing to defend: We are not worried about others' opinions or about being attacked. There is a Buddhist story about a monk who was falsely accused of impregnating a young woman who faced being ostracized by the villagers for giving birth out of wedlock. The monk endures quietly the anger and judgment of the villagers; he does not deny, defend or explain and even accepts the responsibility of raising the child, in spite of his innocence. As it tends to do, the truth eventually comes out when the real father returns. Without hesitation, the monk returns the son to his parents even though he has raised him as his own for years. The monk was exonerated, but the point is that he was free all along and did not need exoneration. Even when he knew he was right and despite the injustice and lies being told against him, he remained silent. That's freedom. That's power. No need to defend; no need to explain. His state of being and sense of self-worth did not depend on what others thought or how they felt about him.
Defensiveness is an intrinsic trait of the ego and characteristic of the human condition. We feel attacked, questioned, misunderstood, victims of injustice. We feel compelled to prove our innocence, our rightness. This is the case especially when confrontation triggers deep issues of identity -- how we perceive ourselves. Yet why is how others see us so important? The more we shift our focus internally, the less external validation is needed.
Not taking things personally is key. Not everything is meant to be an attack or hurtful or an affront to our integrity. Sometimes people are simply acting out their own pain. There is no need to take it on. Let them have their experience. Be compassionate. Sometimes they are just working out their own insecurities, issues of trust or overcoming perceived powerlessness in themselves. We must rein in our projections about others' motives and stop ascribing meaning to their actions. Who knows why people do the things they do, what's going on in their lives or what they are projecting onto us?
This does not justify anyone's behavior, nor does it mean that we get to write off or ignore all the feedback that comes our way because people are just projecting their stuff onto us. Which they are. We simply learn to "put on our seal suit" or, like an old Cuban expression says, "darse un bano en kimbombo," meaning to "take an okra bath." In other words, we let things slide off us and don't get snagged by them.
However, there are aspects of others' mirroring that could have elements of truth and that can support our own growth process, particularly when we receive the same feedback from more than one source. In that case, we take it in for honest consideration without making ourselves wrong or plummeting into failure or shame. Instead, we look at it as objectively as possible with self-compassion and a constant commitment to growth and self-improvement. This takes self-knowledge and a lot of work on oneself, but who else will or can do that for us? This is about our personal freedom, ultimately.
Although it may seem counterintuitive, authentic, vulnerable communication has great power. When we make ourselves open and vulnerable, behaving in a way that extends and elicits respect, that tends to generate the same in the other. Whereas normally we think of someone vulnerable as weak, it can be the exact opposite. Being consciously vulnerable, dropping the defenses, entails a certain level of self-knowledge, security, self-awareness and self-acceptance which are all foundations for personal power.