Today, my friend Kim leaves Seattle to return home to Ohio. It felt important to talk on the phone one last time on West Coast time before she headed back. When I asked about the final packing and cleaning, she noted that her daughter didn’t care for the echo in the empty rooms, a sound that I agreed is eerie, whether one is coming or going. I think it’s the ambiguity — the hollow tones of an unfurnished space denote change, and with all change comes uncertainty.

Afterwards, I thought of the places I’ve lived and the transitions that came with moving, including the space I reside in now, a lovely 1930s building with built-in shelves, cabinets of dark wood and grand closets with heavy doors. It’s the most favorite space that I’ve laid claim to, perhaps because it’s also been the most mine. It’s warm and cozy (how I love boiler heat on 19 degree days) and surrounded by greenery. From my living room, I can see the Space Needle, which now sports a headdress of lights in the shape of a Christmas tree at night.

With well-stocked bookshelves and mango wood side tables, the microsuede green couch and the cocoa brown wood dining set, my apartment feels substantially settled. Like all new homes, it didn’t feel this way when I moved in four years ago, greeted by tenuous echoes in every room. Would I be happy or lonely here? It was hard to say. I was so hell-bent on extinguishing those vaulted tones that I stayed up until midnight each night for a week until everything was in place, right down to the last wooden spoon and pair of scissors.

Much has happened since –jobs, travel, friends, writing, love, loss– that I might have lived here a decade. Today, things continue to change so dramatically and quickly that I feel surrounded by transiting footfalls even though I haven’t moved. Rites of passage are everywhere: friends getting married and having babies, moving across the country and to foreign countries, coming and going at work. Sometimes, I consider the greatest gift to be the few hours I have alone in my apartment to pause and consider all of this rapid change because it would be easy to be too busy to notice.

But how often do we ever know what’s going on inside someone else? How often can we see a person and still not know what rounds out the rest of her life, let alone her mind? This year I’ve become friendly with a kindergarten teacher who works out at my gym. We talk each morning about weekend plans or what’s happening at her school; it’s not a close friendship but a regular exchange. Over the summer I ran into her at a catered dinner, only she wasn’t attending, but serving the food. When our eyes met across the room, she smiled and walked over. “Hi, it’s S– from the gym.”

“Hello! Yes, I recognize you, but…”

“Oh, I cater during the summers. Actually, I work another job part-time, too.” I thought back to what she had said about teachers’ salaries, feeling tongue-tied as she went about organizing the silverware. It was like seeing one of my own teachers bagging groceries. Three jobs?

As she laid out wine glasses on the white linen, I felt like I should offer to assist. If we were anywhere else, I would be helping her, not expecting her to serve me like a princess. I felt guilty about my misplaced embarrassment –after all, there’s nothing shameful about working a catered event– yet I couldn’t help but think about the economic divide that had her working at the same dinner where I was an invited guest.

She and her co-worker stood at the back of the room, attentive yet clearly bored, as the evening dragged on. There too much wine to fuel our bourgeois conversation about writing, the art world and the new director’s condo. We waved at each other when I left, but haven’t spoken of that evening since. I was going home to my apartment to relax for the weekend; she stayed late to clean up after us (me), then worked the next day at a retail job. This was how she spent her summer vacation.

That night, my heart sank at seeing how poorly we compensate our teachers. I also realized that I didn’t know her very well at all. That disappointed vacancy, I realize, is similar to an apartment or a relationship in transition. The bittersweet inevitability of letting go, of acknowledging how things are, catches one’s breath. One might have feigned happiness or adapted to certain constraints for years, a tacit contract with an equally yoked partner, but when the arrangement no longer works, the physical proof is undeniable.

It was that way when I separated from my husband years ago. Our last day in that ill-fated house, which needed far more work and money than we could provide, we felt like we had failed. It wasn’t something said aloud, but a shared chorus of a dusty A-minor chords lingering inside. After a decade, we had given up and let each other down. The house had represented what was happening inside all along, though we didn’t want to let that truth be realized; it took several years to arrive.

Friendships, on the other hand, don’t always have a shared space to use as a mirror. Instead, there’s a vague feeling of displacement when one person pulls away without indicating her intentions. Suddenly, it’s too quiet. She’s packed up and moved her boxes without notice. One day, her friend comes home to find nothing but a bare lightbulb suspended from the ceiling and no forwarding address. Sometimes, we’re changing so fast that we don’t even realize it ourselves, each of us moving on, slowly drifting away until the emotional distance is too far to bridge, even if the person lives a few blocks away.

As I prepare to say farewell to Angela, who is moving to Melbourne, Australia at the end of the month, I realize that I need to be more mindful of what’s happening in all of my friends’ lives. Maybe it’s the product of living in a busier, more distracted society, but it feels like we are charging forward, me included, without sharing more than a Facebook status or update over text. We may learn details via technology, but no longer feel the impact of our friends’ growth and development in visceral ways.

The other day, my bus was technology-shamed by a Brit who crisply asked her four-year-old daughter, “Look around right now; can you tell me what everyone on this bus has in common?”

The curly-haired girl took a minute to peer down each side of the articulated bus, then said, “Mm-hmm.”

“That’s why we have rules about computers and phones at home. Let’s have a conversation instead of staring at tiny glowing boxes, shall we?”

Fine, I thought as I checked work email, give me my &*%$ scarlet apple to pin on my jacket. Though I wanted to stick my tongue out at her, she had a point. Friendships, as much as general consciousness, are hard enough to maintain alongside careers, family and one’s personal routine; add email, social media and Scrabble, and the quality of our interactions –the human quality– shrivels into a thin veneer before we know it.

As the New Year approaches, I’m thinking about what I hope to experience and try in 2014, not just on my own but with my friends. Like a new apartment, the bright side of change is a clean slate, the possibility of moving our familiar qualities into new configurations that weren’t possible before. With different and changing conditions, we can add elements that we couldn’t previously accommodate and discard elements that no longer suit us.

Perhaps instead of echoes, the sound of vacancy is more about openness and expansion, like a pealing bell whose rich reverberation reaches farther than the original notes could have on their own.