She was punctual. I was late – totally consistent with our respective styles.

There sat my granddaughter, patiently waiting for her frenetic grandmother at the restaurant where we were meeting on a recent afternoon. Hannah was about to return to her junior year at Barnard College after a recent break, and I was determined to have some “face time” with her before she left.

Hugging her tight, I was remembering another hug on an August night, the one just before this granddaughter left for her freshman year of college. Standing on her suburban lawn not knowing quite how to say this goodbye, Hannah made it easier for me. She gently released herself and walked away first without looking back, knowing what she would see: a weeping grandmother forcing herself to get back into her car.

This spring, she’s not the same 18-year-old who left us on that summer night. These days, our granddaughter is able to maneuver the teeming streets of New York City – and in a larger sense, to find her way into real life and adulthood.

At our lunch, she smiles indulgently when I lecture her about safety. No, she assures me, she doesn’t ride the subways alone late at night or venture onto unfamiliar streets. I need not worry.

Ironically, there are subtle reminders now that Hannah is looking after me. When I forget to pick up a roll at the restaurant’s salad bar, she is instantly on her feet to get me one. When did this modest caregiving start? And where will it take us a few years from now?

My granddaughter has been determined to find a summer job that will do some good in the world and also help defray the costs of her tuition. And she’s been granted a summer fellowship to do just that.

Hannah is part of that beleaguered generation facing annual tuitions that cost as much as homes used to. So she juggles several part-time student jobs with class work. When I try to tell her I’m proud of her, she changes the subject.

College has widened Hannah’s horizons. This year, it’s noticeable.

She reminds herself to send me a recent paper, using her iPhone as her personal assistant. Hannah has never known a world without computers and technology. Via that phone, I’m soon looking at photos of her roommates, her sorority sisters and some young men who live across one campus block at Columbia.

Will one of them break her heart – or win it for keeps? It’s shocking to think that at her age, I was already engaged to her grandfather.

When we stand to leave, I want to fight back time. I always do at these moments. Later, back at my computer, I see that Hannah has sent me that paper she’d promised. I drop everything else and read it. Or try to.

It’s about stigma in Sophocles, and I understand about one-fifth of it. I’m stunned at the scope and depth of this college junior’s insights and wisdom. I send Hannah an email telling her that.

But there is no real way to tell her how being with her at this stage of both our lives feels more urgent, more wonderful and yes, more bittersweet than ever before.

My granddaughter has gone from little girl to woman to person. She is rushing into the world at the very same stage when I am gradually retreating from it.

But this I know: However numbered they may be, for the rest of my days, I will hope that my granddaughter finds out what really matters in this life. And not all of it comes from courses or books or professors, no matter how brilliant.

Hannah, our college junior, is well on her way. And I am overjoyed – and humbled – to cheer her from the sidelines.