A while ago, years probably, the way things are blurring together, someone gave you an idea for a picture book.

“Doorways,” was the idea, which was passed along to you in a three-degrees-of-separation kind of way.

That’s the kind of idea you like. A better word for it would probably be “challenge.” One word, nothing too specific, bedeviling in its abstraction.

Doorways. Look at it long enough and it looks weird, dour even, maybe because of that beginning DOOR.

You picture some of the doorways you’ve known in your life, the literal ones: the many-paned one that led from the kitchen to the dining/living room in the house you grew up in, the door that was never closed because the house was “heated” from the woodstove in the kitchen.

The small door that led to the tiny triangular bathroom in your first one-room apartment, the door that people who didn’t know you assumed led to the rest of the apartment,  the “real” apartment.

The doorless doorway of your friend’s childhood bedroom.

The doorway of your youngest child’s room, hung with beads.

The chained door that you’ve thrown yourself against more than once.

The door that you tried and tried to open, only to come away with the knob in your hand.

These are a few of the doors you’ve known. Passages from one place to another, doorways that you step through. Now you look down at your feet, those long feet that have walked you from one place to another all your life, some you wanted to go to, others that you didn’t but had no choice.

How do you write a picture book about doorways? What can you say? What does it even mean? Think of a song. Make up a little song. Make up the kind of song you used to make up when your children were babies.

“So many doors in all your days

So much to wonder about –

Who will you be and where will you go?

And how will you know?”

You didn’t think much about who you would be and where you would go, way back when. You wanted to go everywhere, and you were young, and you went far, and often alone.

The age you are now seemed unimaginable when you were young, but you don’t feel much different. You’re more patient now, not by nature but by necessity. You’ve let go of some of the things you wanted so fiercely, not by nature but by necessity.

You’ve gone places you longed to go – children and books and friends and loves – you’re lucky. You’ve gone places you never wanted to go, never would have chosen to go – funerals and heartbreak, loss that felt too painful to bear – you’re human. To be human is to love what is mortal.

How do you go from one place in life to another when you don’t know what’s coming? How do you keep going? How can you fit a lifetime of wonder and longing and heartbreak and love into 32 pages?

Can you?

You keep trying. You think of your own children. You don’t want them to hurt, to go through those sudden terrifying doorways that they, being human, will someday have to go through. Will they know that you are watching over them?

You imagine a bird, a kite, earth and sun, the unimaginable depths of that dark ocean. You keep returning to that refrain: How will you know? Sometimes you won’t, is the answer that comes back.

So many doors in all your days

So much to wonder about

Who will you be and where will you go?

And how will you know?

You think of your children again. Please, let them know that you will always be watching over them, no matter where you are, where you have gone.

You are loved more than you know.

And finally it’s a book.  “So Many Days,” illustrated by the quietly brilliant Taeeun Yoo, edited by the wonderful Caitlyn Dlouhy, due out next week from Atheneum. Up top there is the cover.