Today marks the 7th anniversary of when I started at Facebook.

Writing that first sentence gave me a moment of pause. It’s like saying Shanghai is the most populous city in the world. Both are statements of fact, succinct and precise, but lacking in any sort of impression. Shanghai is my birth city, the first place I remember growing up. To me, populous means living with my relatives—six families in total—in a single three-story house where gossip and the smell of hot-oil cooking snake up the walls like vines. It’s malls that feel like subways, and subways that feel like a childhood game of sardines. It’s noise noise noise—cars honking, bike bells clanging, vendors shouting, people yelling and laughing and talking over each other at big circular tables made for twelve—noise so comforting, so familiar, that a moment of silence feels alien and hollow.

Seven years at one place isn’t what feels significant. Certainly it is long by Silicon Valley standards (my husband has, in the same period, been a part of 5 separate companies), but time itself is not all that interesting. My parents have both worked at their jobs longer than seven years. So have countless others.

Neither is the significance of that first sentence wrapped up in the fact that I worked those years at Facebook. I don’t say this dismissively. Of course a company as significant as Facebook is rare, inimitable from a thousand different angles. It is a company I am proud to be a part of. The odds are good that nothing else I do will come close to rivaling the impact of my work there.

But the feeling here seems more universal than a certain company for a certain period of time. I think many of you, regardless of whether you share my exact history or not, will know what I mean.

There is a saying that you make your habits for the first thirty years, and then your habits make you for the next thirty. I am not too far from that magic number, the big three-oh. Already I can feel the stirring of that process, slow but assured, the making of a person. The hardening of certain principles—personality, values, core beliefs—like pieces of sculpted pottery drying in the sun. I do not make decisions impulsively. I do not gush. And a beautiful string of words will always set me alight.

You might blame that on a certain concoction of genes. Environment, too, surely plays a factor. I’ve written before about the mystical power of friendship, but all powerful relationships are written in the folds of our skin. And the past seven years are, to me, a relationship with that kind of power.

Yes, a company is an entity, a dynamic organism. It has the capacity to change, but it also has its own soul. When it hums and breathes, it does so at a specific frequency. It can be inspiring and beautiful like nothing else, the whirring of dozens of minds and hearts in synchrony, hoping together and aching together. Hands crafting something larger than an individual could possibly accomplish. The company sings of a dream that feels ambitious and pure, that draws you in so you can’t help but sway along, throat shaping those same notes, head bobbing along, eyes bright.

And like with all real, living things—the company can be terrible as well. It lets you down. It frustrates you. You awake some days to find that it has strayed from its promise. That it has made a mistake, or ten, or maybe a hundred. That its insides are twisted up like snakes, and chaos has descended like a stormcloud, thickening the sky so you can’t tell north from west.

But through all that, the thing that is significant, the thing that really matters, is the way that sort of relationship changes you. Whether it’s a person, a family, a city or a company—some experiences craft you into the person you are. That you will be. A relationship can demand from you the type of growth that you never thought possible. Teach you lessons that you didn’t even know you didn’t know.

I was 22 when I arrived at Facebook clutching a newly-minted CS degree, not knowing much about companies, not knowing even that design was a career. I interviewed because I liked and used the product (then still a college social network) and because a friend told me it was a great place to work. I did not ask questions about strategy or culture or where the company hoped to be in 10 years. I did not ask about the competition. I did not even ask what I’d be working on. (Conversely, even though this was supposed to be an engineering interview, not a single interviewer asked me to write code.) Facebook was a young company full of people my age, reckless and clueless. We stumbled and hacked our way forward. We learned how to build things. Together, we grew up.

It’s impossible to imagine what life would be like had I not spent most of my twenties at Facebook. I’d have a completely different set of friends. I might be living somewhere else—across the pond, in the woods, at the edge of a big mirrored lake. I might not even be a designer. Perhaps in this blog I’d be professing my love of closures and dynamic typing, or detailing the recipe for a perfect mille feuille because I’d become a pastry purveyor. It’s not to say that another hypothetical life would have been better or worse. Only it wouldn’t be this life. Only that I would not be me as I understand myself to be.

This is what feels significant.

I’ve heard the analogy that companies are sometimes like families or significant others, and this is perhaps nowhere more true than in the intense whirlwind of a startup. When you are young, when you have few other attachments and responsibilities, love for a company can be its own brand of love.

Thank you to everyone I have had the pleasure and honor of working with. Through my past seven years at Facebook, I grew up.