Lifelong friendships are rare — and that’s part of what makes them so special.

We’re not meant to have the same set of friends throughout our entire lives. We move to different places, we change, we drift apart. Sometimes we outgrow each other — and that’s perfectly normal. But the friendships that last for decades are truly something to cherish.

So what do lifelong pals do differently that keeps their bond so strong over time? Read on to find out.

1. They show up for each other when it matters most. 

When you’re friends with someone for many years, you’ll inevitably see each other through some of life’s biggest challenges: the death of loved ones, breakups, divorces, layoffs and health issues. Fair weather friends may fall off the map when the going gets tough. But lifelong friends know they can count on each other to be there through it all with a listening ear, a shoulder to cry on or just a welcome distraction from the heartache. 

“When we do show up for one another in these moments, it solidifies our bond,” psychologist and friendship expert Marisa G. Franco told HuffPost. “People get to experience how much others truly love them by witnessing how much they show up for them in times of need.” 

2. They plan for transitions — and keep talking once they happen.

Lifelong friends are proactive about figuring out how they’ll continue to fit into each other’s lives, even as circumstances change — whether it’s a cross-country move, a baby, a new career or a romantic relationship. 

“They plan a visit before their friend sets off to a new city, low-key hang out in-person or virtually while their friend takes care of their infant, or schedule regular ‘friend nights’ so that a new romantic partner doesn’t crowd out time for their friendship,” said Rhaina Cohen, who covers human behaviour as a producer for the NPR podcast ”Hidden Brain.”

Of course, no amount of planning will makes these transitions seamless — there will be growing pains along the way. It’s the willingness to adapt and put effort into maintaining the friendship that counts.

“If you’ve already made it clear to each other that you expect to work through challenges created by the transition, you’ve created a runway to articulate how you feel and make adjustments,” Cohen added.

3. They remember things happening in each other’s lives, big and small.

Friends might text you on your birthday, but your nearest and dearest pals go a step further. For instance, they never forget to reach out on the anniversary of your mum’s death or send you flowers or your favourite dessert. They also remember to check in on things you may have only mentioned in passing, like an upcoming job interview or a doctor’s appointment you were nervous about.

“Remembering each other should really be more about remembering the less obvious things,” said Kurt Smith, a therapist who specialises in counselling men. ”Some examples could be that their mum is getting chemo treatment, their daughter is applying to college or they’re remodelling the kitchen.” 

4. They’re able to discuss issues in their relationship honestly and maturely.

Lesser friends might sweep their frustrations or hurt feelings under the rug, too scared to tackle these problems, hoping they just disappear. Lifelong friends, however, are committed to addressing whatever issues come up. They’re confident their friendship can withstand uncomfortable conversations, and know that having them will only strengthen — not destroy — their bond.

“Research finds that we tend to distance ourselves from friends when problems go unaddressed for too long,” Franco said. “Other studies find that open, empathic communication around conflict strengthens relationships. Bringing up issues is a way to honour the relationship, and lifelong friends know how to do it in a way that doesn’t involve blame, but instead involves working together to heal from issues.” 

5. They’re vulnerable with each other. 

Unlike casual friendships that tend to only scratch the surface, lifelong friends know they can let their guards down with each other. They can talk about their fears, their flaws, their mistakes and insecurities and know they won’t be judged or rejected.

“Lifelong friends tell each other what’s really going wrong,” Franco said. “The strength of a relationship is revealed by the degree to which we are willing to express our truest and deepest selves within it. This willingness to be vulnerable conveys trust and strengthens the relationship.” 

6. They make time for quick catch-ups and longer get-togethers.

To maintain the long-term friendships in her life, Cohen said she aims for a mix of brief check-ins and extended hangouts.

“For me, exchanging voice memos or having a standing monthly call ensures that a friend and I have an up-to-date sense of each other’s lives,” she said. “These discussions mean we don’t have to dedicate our longer hangouts to ‘catching up’ — i.e. recounting our lives’ basic plot lines without moving the relationship forward.”

Those regular check-ins keep the friendship humming along. But without longer hangouts (when you can ideally spend a day or more together) in the mix, it’s difficult to have those unexpected conversations that take the friendship to the next level. Lifelong friends know how nourishing this extended time together can be and prioritise it when they can.

“I find friendships strengthen when we have occasions to spend more than an hour or two together — even if that’s only every year or so for my long-distance close friends,” Cohen said. “Hikes create an excuse to spend the better part of a day together, as do vacations or visits.”

7. But they also give each other grace if they go a while without talking. 

In an ideal world, we’d keep in touch with our pals regularly, but sometimes life gets in the way. Long-term friends understand these ebbs and flows and try not to take them personally. In time, they come back together and pick up where they left off.

“Part of being a lifelong friend is recognising that your relationship has value regardless of how much or how often you connect,” Smith said. “Staying aware of the fact that your friend has other things going on in their life, including other friendships, and not being offended when you don’t connect every day is a real gift that can make friendships last a lifetime.”