When I was five years old, I met Betsy. She lived down the street and around the corner from my childhood home in a Colorado subdivision called Village East. Betsy was a year younger than me, our parents were of different generations, and we practiced different religions. But in nearly every other way you could imagine, we were similar enough to have been sisters.

Betsy and I walked to school together. Sold Girl Scout cookies together. Rode our bikes to the YMCA to go swimming. Giggled endlessly over shared secrets. We even made up a special, abbreviated language that only we could understand. We rode sleeping bags down the stairs, sold lemonade and painted rocks to neighbors, and made movies to submit to America’s Funniest Home Videos. We could spend days together and never get bored. We had a way of rolling through conflict in a matter of hours—if not minutes. Our parents marveled at the fact that year after year we never seemed to get tired of each other or run out of things to do.

It was only when I moved into the sixth grade and off to middle school that we drifted apart. In high school Betsy’s family moved to another neighborhood, we each made different friends, and we went to college in different cities. And as we became adults our lives took different paths. But over the years we have kept in touch—attending each other’s weddings, occasionally reminiscing over text about quirky things we used to do together, and watching as our kids reached the age we were when we first met. If they were neighbors, we wondered, would they be best friends just like us?

What defined that relationship for me was the familiarity and dependability—the sense that my friend would always be there, and that in her my most authentic self would always have a home. It was knowing I could find an extra swimsuit at her house when we decided to run in the sprinklers. And a place to be a kid again when my home and family became overwhelmed by loss and grief. It was the reliable, lived-in quality of two lives intertwined by hundreds of shared memories, experiences, laughs, and lessons. That was how I knew I had a friend.

What does friendship mean to you?

That’s number sixteen on a list of 36 questions friends and lovers—even strangers—can ask each other in order to fast-track their relationship into a deeper, more intimate connection. Some of the responses I’ve heard as I’ve asked it again and again this month are below. But when I first came upon that question, my answer was Betsy.

What’s yours?

Vulnerability, openness—the feeling that I can say what I’m really thinking.

Loyalty. It’s knowing that no matter what, my friend will show up for me. Even when I screw up.

I like to feel like my friends are willing to spend the time it takes to really give and receive support. So I think for me it’s about availability.

Trust. Like I could trust them with my life. That’s what matters most to me.

Being known—the feeling that all the things that make me unique are seen and valued and remembered by someone else.

Long-haul time commitment.

That easy sort of feeling of history. Like a sense of depth—that there’s a well of shared experiences that have cemented our friendship over time.

The ability to laugh. Or just having fun. A friend is someone who can lighten the load of life by reminding you to just laugh through it.

Friends are the ones who don’t judge. They give advice or tell me when I’m making a fool of myself, but a true friend is someone who just accepts you—as is.

Someone who stands up for you in a fight. Or protects you. A friend stands between you and the bully.

Generosity.

All the crazy memories we’ve made together. Stories. And sometimes those stories are things you can’t really share with anyone else.

No filter. Just being who they are—100%. Which gives me the freedom to do the same.

For me it’s communication. Like when it’s just easy to say what you mean and feel understood.

Honesty. A good friend will always give it to you straight—no matter what.

Reliability. Being there in the good times and the bad.

A friend gives you the feeling of never being alone in the world.