They grow up so fast.

I have been watching the goslings at the Arboretum grow up. I walk my dog there in the morning and evening, and now that it’s a summery spring we also sit and bask in the sun, the glow of the rippling water, and watch the goose kibbutz in action.

I have learned the intersecting territories; where the redwing blackbird nests are, the favorite sunning place of the giant black rat snake, and that of the angry old squirrel who always yells at us to get off his lawn. One day a baby sparrow hopped straight at me as we ambled the path, and opened his beak when I bent down to inspect him to see if he was hurt: feed me! I rubbed his head with one finger, apologetically. Sorry, buddy: just ate my last worm. My peaceable little dog watched this transaction with bemusement. The magnolia has already bloomed and lost its fragrant flowers. They also grew up fast and flew away one night – faster even than the geese. The lilac bushes and honeysuckle are hardier specimens, and their perfume mingles with the rich scent of loamy decay and rebirth from the dark shadow of the riverbanks. It’s my favorite smell – two parts solar joy to one part cool underworld. Mix and inhale.

Now the goslings are getting pretty big – they’re still more fuzz than feather, but they have some adolescent swagger. Nevertheless, when the adults spot the hawk who likes to hunt at the Arboretum, they launch into an impressive battle formation, all warlike honks and widespread wings. They circle the pond where the little ones swim, swooping in a deep circle around and around it, flying sentinels. The geese are no joke, actually. My dog hasn’t earned their ire, but a combative Corgi recently did and it was one hell of a sight. The geese will cut you if you look funny at their babies; this is the right reaction.

They grow up so fast.

A little girl on a small pink bicycle is pedaling toward us, her tinsel-festooned handlebars twinkling in the dusk light, her rainbow-socked legs powering that bike for every scrap of speed she can get out of it. I wave; she waves back. She looks like she is about seven, which is how old Samantha is.

They grow up so fast.

I remember how intrigued Sam was as a toddler with stories about when she was a baby. She is fascinated, deeply fascinated, by the concept that she has an existence that predates her own memory. The degree of her fascination rivals that of the protagonist of any amnesiac movie. That she was here, and a baby, and we remember all of it, but she does not. How can this be? She looks at pictures from her own baby album. Tell me about when I was a baby! Is one of her favorite requests.

We are all at the dinner table for Thanksgiving, and she is a little older than two, and Nana is coaxingly telling her about how much she loved mashed potatoes when she was a baby (because she will not touch the stuff now). I casually mention that I remember when she was even SMALLER than a baby, and this gets her attention right away.

Nobody has mentioned a smaller-than-a-baby history up to this point. She looks at me, her little eyebrows raised. My brother and sister-in-law look at me, their eyebrows also raised, wondering if I’m going to nerd out about embryology to their toddler. But that is not my plan.

“Oh yes,” I say. “I remember when you were so small we could carry you in the palm of our hands. You were so, so tiny! You had shoes made out of peanut shells!”  Her eyes widen. “You wore dresses that Nana sewed for you very carefully out of rose petals, because they are soft and smell good. You wore them with your peanut shell shoes and tapdanced on Papa’s plate after dinnertime, and we all clapped!” Now she is grinning. Her eyes are still big, but her gaze is beginning to turn inward as the gears turn and she pictures everything I say.

“You slept in a bed made out of marshmallows, and used Papa’s handkerchiefs for sheets!” My mother chimes in now – “And sometimes you would hide in my gloves and pop out and say HERE I AM!” Now Sam looks positively delighted. “And best of all,” I say, seeing an opportunity to allay her fear of spiders, “You had a giant spider that you rode like a pony!” She grimaces and squinches her eyes shut, then opens one eye back up in curiosity. “It was a fuzzy spider, and you named him Sir Galahad, and we made him a velvet saddle. You would gallop that spider all over the house, and we could hear your teeny tiny voice yelling yeeee-haaaaw!” The business with the spider is too much - Sam finally looks at her mother and father for confirmation of these marvels, and they give her this look like “I sure hope you’re not buying this bridge, kid.”

Sam thinks about this for a minute, her little two-year-old brain working overtime, and then bursts out in a gale of laughter so loud, so sudden and huge, that we all laugh too.

“Aunt Sarah! You are IMAGINING!” she whoops delightedly, looking at me with glowing eyes, like I have performed an unexpected marvel.

She’s so cracked up by this, so amazed that I’m doing this right in front of her! Like flying, like juggling, like singing a song while standing on my head. I’m imagining, live and in person and out loud RIGHT IN FRONT OF HER! This is too much! She is laughing her tiny head right off.

“Yes, honey,” I reply owlishly, wiggling my eyebrows at her. “I love to imagine!”

There are many firsts I have enjoyed with this child – it was my principle joy to bring her the first taste of many things. Kiwis, tofu, dragonfruit, capers, Turkish delight. I would tell her about the lands they came from, about the people who lived there. She has been talking and listening since she was 18 months old, so this worked out fine. Her first complete sentence to me, uttered I hovered protectively around her while she toddled unsteadily from room to room, was “Aunt Sarah, you really have to stop following me everywhere.” This cracked me up, as family legend has it that my first complete sentence was “You can make me, but I will not cooperate.” Child of my tribe.

But this taste is the best of all: it's evidently her first taste of seeing an adult make stuff up

Now she is seven going on seventy, and her catchphrase is “I know that.” But I can tell she secretly likes it when I imagine out loud about things like what it would be like if we were all fish, even though I think her parents are raising her to be a very matter-of-fact Midwestern girl. She is fond of me and my imagination, which I think she views as a kind of amusing sidekick of mine, like a talking parrot. She recently informed me that I am the best Aunt Sarah in the world, so all the other Aunt Sarahs are officially on notice.

But really, all we are is our imagination; when we plan for the future, we are using our imagination to forecast events. When we are remembering, we are using our imagination to reconstruct a past event. It is only when we exist in the absolute present that there is no imagination, but only the fact of existence. Those are the moments that shape us the most; ironically, they're also kind of rare

We imagine meals as we write shopping lists, imagine sunny days at the lake when we buy wide-brimmed hats, imagine not feeling so groggy as we brew our first cup of the day, imagine little girls grown into women as we carefully tuck away silver shoes with rhinestone buckles that will fit them in fifteen years.

I’m walking my dog at the Arboretum, and I am imagining. I imagine sitting down to write this. Writing it, I remember imagining that. Who needs Inception? The whole thing is kind of automatically mind-blowing.

On the best evenings, I do not imagine anything at all. On the best evenings, there is nothing but the sweet twilight breeze and the lilac sky, tiny coins of gold still sparkling on the water, birdsong, rest, and my gentle little dog's head warmly propped on my leg as I sit stretched out on the dock. I will need that moment later; the memories of what it is like to simply be.