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Some friendships are relationships you’ll have for the rest of your life, but unless you’re very, very lucky, those aren’t the norm. Most often, friendship looks like something messier: People will float in and out of your life as you change, or they change, or circumstances change. There are moves. There are fallings-out. Schedules get busy. You’re probably not still super tight with your seventh-grade best friend; in fact, as you enter your 30s, you begin to shed a lot of the friends you made in your earlier years. In most cases, that doesn’t mean you’ve banished those people from your life forever; it just means you’ve gone in different directions. Maybe someday you’ll find your way back.

But reviving a friendship that’s died requires more than just hitting the play button on something that’s been paused, explains Irene Levine, a psychiatry professor at NYU and the author of Best Friends Forever: Surviving a Breakup With Your Best Friend. It’s not as simple as just picking up the relationship you had before. It’s also more difficult than starting things from scratch with someone new. Here’s her advice for how to get things rolling with a new old friend.

Think long and hard before you start things up again.

Whether you broke up with some sense of finality or just let things fade out, there’s a reason you ended things last time around — and whatever pushed you two apart may not have gone away. “Sometimes we romanticize our friendships, and maybe we forget some of the reasons why we ended [the relationship],” Levine says. “You might be going back into the same morass that you left.”

Before you try to reach out, then, it might be wise to take some time and do a friendship postmortem: Were you too busy to make much time for each other? If that was the case, has it really changed? Or, alternatively, if you couldn’t stand the way she sucked at listening and made everything about her, what makes you think you’d be okay with it now? “If you think it’s going to be a completely different person than the person you broke up with, you’re probably being unrealistic,” Levine warns. That’s not to say that they haven’t gotten better, or that it’s not worth giving things a shot — just that you should be clear-eyed about what makes a friendship deal-breaker for you, and be prepared to abort the mission if you need to.

Pretend you’re getting to know them for the first time.

Especially if you’ve just moved, it can be tempting to contact everyone in your phone that lives in your new city — an old camp buddy, an elementary-school classmate, really anybody who’s ever been more than an acquaintance. That’s understandable! While making new friends can be a little awkward and daunting, the whole dance is a bit more comfortable with people you were once close to: “You do have a foundation of shared experiences,” Levine says. “So it does give you a jump start in the friendship.”

Still, that doesn’t mean you should immediately assume the same level of intimacy you once had. “You might want to try to become acquaintances first, rather than friends,” she says. You may be starting slightly further ahead than you would with someone brand-new, but you’re still going to want to let things unfold at the same pace as you would after hitting it off with a stranger. Start with coffee, not a spill-your-guts vent session.

Because, in a way, they are. Even if you have that easy, clicking, friendship-at-first-sight feeling once you see them again, it takes more than a spark to make a relationship worthy of your time. “You really need experience and time to build trust with another person, whether it’s an old friend or a new friend,” Levine says. Ease often complements things like trust, but it isn’t a stand-in.

Besides, that sense of instant reconnection might be one-sided — we can often be blinded by our own desire to make things work, whether out of loneliness or excitement over having this person back in our lives. And that optimism can make it easy to miss red flags, or signs that the other person isn’t as into the reunion. “You might misperceive social cues, [or] she might not be listening when you think she is, or she might be judgmental and you don’t realize,” Levine explains. If you run headlong into insta-friendship, you might not notice that it’s not a fit until after you’ve already invested time and emotional energy. Being cautious, on the other hand, keeps you from that’s pouring yourself into a relationship that’s a nonstarter; if things progress more slowly back into genuine friendship, it’s more likely to be a real, sustainable bond.

Give them time to process (and don’t take it personally).

Another way to make sure you’re both equally invested in reviving your friendship: Don’t pressure them into starting things right away. Email is better for first contact than a call or text, Levine says, because it’s less immediate. “It gives the other person a chance to think about it,” she explains. “Just because you’re ready to rekindle a friendship doesn’t mean the other person’s ready — you’ve given it a lot of thought, but the other person could be caught off guard.” If they’re into the idea, great! Make that coffee date.

If they blow you off, though, try to keep in mind — even though it’s easier said than done — that it’s probably more about them than about you. “The other person may be fully engaged,” Levine says. “They may have a lot of friendships, they may be juggling work and personal matters, they may not have any more bandwidth to have one more friend.” And that’s the reality of friendships, for better or worse: They’re all part connection, part timing. It’s the reason you can’t hold on to all the friends you’ve ever had. But it’s also the reason that you can know, if you do ever get back together, that there’s a real shot at making it work again — because you’re in the right place at the right time. And if you’re very, very lucky, you might get to a point where you forget you ever hit pause to begin with.