When I meet a person now, even one I think I know well, I try to remember that I am seeing only what they have chosen to show me, and that behind it there may be a whole hidden architecture of fear or grief or struggle that I will never be shown, and that my confident sense of knowing them is, at best, a knowledge of their surface.

Kieran was not a good husband, and our marriage was not a good marriage, and I do not romanticize either.

But he taught me, without meaning to, one true and permanent thing: humility about the interior lives of others.

We are all, to one another, mostly hidden.

The most we can do is remember it, and be gentle with the parts we cannot see.

Chapter 13 — The Key in the Poetry