Sometimes it's helpful for me to think of it from a different angle. For example, what's the opposite of detachment. When I think about Attachment, I see there are healthy and unhealthy ways to attach. I had good models and bad models of attachment growing up and learning the difference has been my task as an adult.
I need to detach from unhealthy attachments like - no longer investing myself in expectations. They're a setup for disappointment. So I've learned to recognize when I have expectations for certain results. Once I get that part of it, I can work on acceptance of reality and let go of attaching my well-being to the outcome. This is the same as recognizing what I can and cannot control. Life's too short to keep attaching to those things I cannot control or have no business controlling. Then what it comes down to is my choice; I can choose to be happy or unhappy.
Until I spent a lot of time developing awareness and understanding about detachment, sometimes the only action I was up to taking was self-protective or defensive. I had to start there. Maybe it was punitive or cold and detaching with resentment or anger. (That's how one starts.) Despite the fact this still kept me invested in the outcome, it was taking steps in the right direction; changing the old patterns. I had to do some experimenting and trying things out and practice a new model of behavior.
As time went on and I better understood what healthy detachment/attachment was, I was able to detach and keep my compassion at the same time; it's a win-win situation benefiting myself and the other. It's choosing healthy limits, setting healthy boundaries and it restores my balance and serenity. It's a wonderful key to peace and happiness.