What Doesn't Change, In Change

This is one of my favorite poems to read aloud toward the end of a retreat on big life transitions...

...mmm, I love the hushed and fertile quiet of a group of women listening deeply, with the ears of their hearts, to a good poem.

In a big transition, so much of what we "knew" about the world — our assumptions and beliefs about ourselves, about life, about relationships and others — goes away, never to return again. Given this, it is life-giving to reflect on what doesn't change, that thread you follow no matter what:

THE WAY IT IS

There's a thread you follow. It goes among
things that change. But it doesn't change.
People wonder about what you are pursuing.
You have to explain about the thread.
But it is hard for others to see.
While you hold it you can't get lost.
Tragedies happen; people get hurt
or die; and you suffer and get old.
Nothing you do can stop time's unfolding.
You don't ever let go of the thread.

~ William Stafford

So what is your thread that you don't let go of, despite changes and how hard it might be for others to see? How does it keep you from getting completely lost?