In our profound in-depth dialogue group on Eckhart Tolle's book A New Earth - Awakening to Your Life's Purpose, we dialogued in depth about that question.
Here is Tolle's summation: Whenever you are upset about an event, a person, or a situation, the real cause is not the event, person, or situation but a loss of true perspective that only space (I call spirit, some call beingness or consciousness) can provide. You are trapped in object consciousness, unaware of timeless inner space of consciousness itself. The words "This too, will pass" when used as a pointer can restore awareness of that dimension to you.
Another pointer to the truth in you is contained in the following statement: "I am never upset for the reason I think."
Eckhart is talking about the "perception of the ego, instead of Spirit." We all agreed.
An inquiry into "what really upset me" can lead me to the inner space of consciousness where peace and quiet can help reveal the answer.
The key is to take a moment and go to Inner Peace, and transform the "attack" back to what is it all about as ACIM states "An attack is a call for love."
Linda's great question: "What if we could be grateful for everything?" can be applied here - to go inside and come back with a "thank you (for asking for my love).
Byron Katy goes further when she is being verbally attacked: "she pauses and goes inside and then states: thank you, I can find that (for example being called a "judgemental bitch"). We all have everything anyway so it really diffuses the situation if we admit it.
"In our defenselessness, our safety lies." ACIM What does this statement mean?
How do you drop your defenses and return to love? How do you respond rather than react?