They were taken completely by surprise. One day they learned their job was ending. They didn't even see it coming. Others made the choice themselves.
I have several clients who are job-hunting or looking for new careers. Some made the choice, and others had no choice. I've been in both places myself—and, personally, I'd rather make the choice myself. But we don't always get what we want, do we?
Either way, though, it's important to reflect on what you have lost in the process. Even when you choose to leave a position and move on, you will experience some losses—whether that be status, a coworker (or more) you liked, connections, flexibility a good health plan or something entirely different.
The same is true when you leave one city and move to another. Or just leave one neighborhood for another. All our "hellos" contain some "goodbyes" that involve loss.
Take the time to reflect on what you're losing and do whatever grieving is necessary for you to let go of the old and prepare for the new. It's important work. It helps you to "clean out" inside and be truly ready for whatever comes next for you. It's the cocoon step of the caterpillar-cocoon-butterfly transformational process. Let go. And then prepare to soar!