Glacier ice is a deep, bright blue, like a giant gemstone encrusted with snow. The dense, compacted ice almost glows; there are no air bubbles trapped inside to dull the pure blue. When a large slab shears off and crashes down,  the gunshot sound of cracking ice hangs in that air as the pieces cascade in slow motion. It is breathtaking.

I was on a cruise ship in Glacier Bay National Park with two lifelong friends. We three have seen each other through junior high and high school, with its acne and Farrah Fawcett hair, crushes and breakups, fashion hits and misses, homework and dances, and assorted moments of angst and embarrassment.

We weren’t together when our huge cruise ship drew up beside the glacier for the passengers to snap pictures in the frigid air. Every railing on the glacier side was lined with tourists craning to see the huge river of ice. When the crack of the ice breaking off rang out, there was a collective gasp of wonder. After marveling at the sight of the calving alone, surrounded by the strangers I happened to be standing by, I ran to the spa to find my friends.

We had separated earlier; I wanted to sit in a chair on the deck with a lap robe and a coffee and read, one wanted to run on the treadmill in the ship gym, and another wanted to relax on one of the heated-tile spa beds. When I got there, they had already left.

I met up with them on the top deck, and was relieved that they had left the spa in time to see the calving; the runner saw the glacier from her treadmill by the window and grabbed the relaxer from her spa nap. I was also feeling guilty that I stayed by the railing to watch the glacier alone instead of racing to find them and make sure we saw it together. We were here to do everything together.

We were having a great time, sharing our little room with two twin beds and one bunk that pulled down from the wall at night. We drank wine around the table on our small balcony, we woke up to hot coffee delivered to our stateroom in the morning, served with a little pitcher of warmed milk, and we tried out all the dining rooms. When the boat docked, we took trips together to see whales bubble-net feeding, to whiz through trees full of bald eagles on a zip line, to take a gold-rush era train to the Klondike, to hike to a melt pond with clear chunks of glassy ice at the foot of a glacier, and to drink beer made from spruce tips at a local brewery. It  was beautiful and wild, the air clean and pure.

I needed a little space, though. My long time friends didn’t recognize this introverted side of their extroverted friend. It became a joke, the kind that covers a little irritation–I was trying to snatch a few minutes alone, and they wanted to hang together. We were on this cruise to celebrate our 50th birthdays, not to hide out alone.

This need to take some time alone to process and recharge, to catch up with my own thoughts, wasn’t a new thing, but I haven’t always recognized the need and acted on it. In the past, I ignored the crowded feeling inside and kept pushing to keep up with everyone until I was exhausted and cranky. It took until almost 50 to interpret the feelings and learn how to bow out of some activities in order to fully engage in the rest of the time together.

It was just one moment among many, many moments together that week, but I can’t shake the feeling that I was selfish, choosing to watch the glacier alone rather than making sure we all were included in the experience, waiting to find them until the show was over.

I do wish I had been standing beside my true-blue friends when the glacier gave birth to its bouncing baby ice bergs, turning to them in the excitement of the moment instead of the nice lady who thought I was lonely and invited me to eat dinner with her. The trick, I suppose, it to pick the right time to soothe my inner introvert.

Compression that leaves no space for air bubbles makes glacier ice brilliant. Even my closest relationships, though, benefit from some well-placed air pockets to keep them solid.