Three weeks ago, Bryan and I became grandparents. My eldest daughter and her husband have just had the most gorgeous little baby girl and like any new grandparents, we are walking around like this is the first time it has ever happened to anyone anywhere in the world.

Amid our jubilation and also relief (like her mother, our granddaughter arrived well past her due date when doctors start getting a bit antsy), what I’ve first experienced on becoming a grandmother is a wondrous déjà vu – feelings that have come flooding back about what it was to be a new mother, the extraordinary journey that I’ve had raising children and that my daughter is now about to embark upon.

One source of enduring sadness for me about modern antenatal preparation for mothers-to-be is that it focuses, almost exclusively, on the pain – the excruciating nature of contractions, the sheer blood-and-guts ordeal of it, the number of things that can go wrong between the start of labor and its finish – and almost never about the dizzyingly, utterly heart-stopping miracle of it all.

I’d opted for a drug-free birth and, yes, it did hurt – a lot. But the central revelation of our elder daughter’s birth had nothing to do with physical pain, and everything to do with the extraordinary primal experience I’d just undergone: a vehicle for someone else’s entry into life.

Within a matter of months, what had begun as a tiny egg had exploded into the quite substantial and fully formed little human lying on my chest, looking up at me right into my eyes.

I was physically exhausted but so overcome by elation that for an entire week I could not sleep. Night after night, I’d lie awake at night, staring at this amazing being next to me in sheer wonder – a wonder so profound and all-consuming that I’d never, ever experienced before.

There I was with a ringside seat to life’s extraordinary continuum. I was the earth and she was a green shoot that had sprouted out of me and that would grow and develop and sprout green shoots of her own.

And then there was the perfect resonance that occurred between us from the very beginning.

I had not expected to be any good at any of this mothering business, but to my astonishment, from the first day of Caitlin’s life, I immediately seemed to be able to intuit what her cries meant and how to make them stop.

“Oh,” I’d say casually, at the first sign of a quivering lip, “she needs to be changed.” Or: “She’s hungry.” Or: “A first tooth is coming in.”

When Caitlin was fussy, no amount of cajoling, cooing, rocking, tuneful singing, or pulling faces by my husband could match simply handing her over to me, at which point her crying would abruptly stop.

I felt like a sorceress with my baby under my spell, but as scientists would explain it, we were in perfect ’limbic resonance.’ Our brain waves had coordinated into a single undulation, a situation beyond simple mirror mimicry, when two people – even two living things – find themselves completely in synch, momentarily melding into a single organism.

At the moment of her birth, I stared at Caitlin for the first time and she stared back at me, and we recognized each other on some deep primordial level. It was nothing less than pure life looking deep into my eyes and inviting me into the very elemental heart of its mystery.

When naturalist Annie Dillard came upon a weasel near her home in Tinker Creek, she described a type of shocked recognition not unlike what I’d experienced:

“Our eyes locked, and someone threw away the key... It emptied our lungs. It felled the forest, moved the fields, and drained the pond; the world dismantled and tumbled into that black hole of eyes. If you and I looked at each other that way, our skulls would split and drop to our shoulders.”

I now see Caitlin’s eyes making that same connection with her little daughter and my heart is filled with joy thinking about the deep place she is about to gain entry to.

Our most immediate role has been one of caretaking our daughter and her lovely husband when needed, with all of the upheaval a new baby brings to upset ordinary routine.

But now that they’ve settled into a bit of a rhythm, I’ve been able to pause a moment to take this all in and sit with a seesaw of emotion.

There is the sheer awe of realizing that your own baby has grown up and had a baby of her own. But there is also the wistful recognition of how this moves you one notch along on the family spectrum and with it, a reckoning of your own mortality – that you no long have all the days left in the world to be there with all of them.

I begin to imagine all the things we will do together, the books I’ll read to my granddaughter, the museums and theater I’ll take her to, the things I did with her mother.

And then when I hold my granddaughter and stare into her eyes, there are the moments when I return to that continuum once more and feel again part of the process: that mysterious, never-ending buzz of being.