Yesterday, I posted an article on Facebook from my favorite advice column, Ask Polly. The gist: A woman had written in because her friends were all getting married and moving on, and she felt marooned in place, single and stagnant. But the column took a darker turn: What happens when you’re in a non-reciprocal friendship?

I posted it because I love Heather Havrilesky’s writing. She gets what it’s like to be human. After I posted it, a few people privately messaged me with stories about how they’d been dumped (or thought they’d been dumped) by friends after their life stages changed. Maybe one person had kids and the other didn’t, or one person ended up marrying somebody the other just couldn’t stand, so she ghosted. Or maybe life just got busy, and the friendship wasn’t strong enough to withstand the test of time and distance and incompatible schedules.

One such person asked me in the course of our chat, “How do I know if I’ve been dumped, or if my friend is just busy?”

So, I have a few thoughts on that.

One: “I’m too busy” really just isn’t a long-term excuse. Each of us has the exact same hours in the day as Albert Einstein, Martin Luther King Jr., Helen Keller, Hillary Clinton and Bill Gates. You make time for your priorities. You make time for what matters. Very few of us are saving the world around the clock. An occasional busy spell? It happens to all of us. But if a friend routinely says, “I’m too busy” for plans and never gets in touch, what they’re really saying is, “I’m too busy for you.” This stings and it’s hurtful, but there’s no point in chasing after someone who doesn’t reciprocate.

Two: Not every friendship is built for every scenario. You might feel “dumped” by a friend if you’re going through a hard time, and he or she just doesn’t react the way you’d hoped. Not everyone does well in those situations (though we should all at least try; it might just be as simple as asking, “How can I help you right now?”). The same person might be a wonderful companion for road trips or movies or brunch. Not every friend needs to fit every need, or even can.

Three: Life stages matter, but they shouldn’t be a deal-breaker. We’re not in high school anymore. We’re not marching through adulthood at exactly the same pace, shuffling from class to class and leaving when the bell rings. Some of us are busy with children; others are busy dating; others are busy building a career (or doing all of these, and more). Fine. You’re not going to live parallel lives with anyone when you become an adult. The trick is not to discount someone else’s life stage as less valid, important or relatable just because you’re not there, too. The friend who needs to vent about her three whiny children might be the one who will also listen to you while you vent about your string of horrific bad dates (or amazing ones). Don’t assume the person in a different life stage can’t relate or isn’t interested. And if you’re in a different life stage, don’t write off your friends’ problems as boring or trivial! They’re telling you because it matters to them. A true friendship deserves that patience. Eventually, you’ll both come out the other side.

Four: Some people are just sincerely unskilled at making plans. Ask yourself if your friend is merely one of those people. Some people do poorly at organizing; some are more than happy to hang out but aren’t natural-born planners. That’s OK! Accept it. If your friend always responds to your overtures but just doesn’t make her own, that might just be how she’s wired.

Anyway, my final piece of advice was once given to me long ago about a business relationship, but I think it applies to friends, too: “Only do business with those who do business with you.” If you feel like you’re in a one-sided friendship, do a final check-in, see what your pal comes back with and if it feels false or unsatisfying, bail. As we get older, it’s so important to make time for the relationships that nourish us and that we can count on. You don’t need to be a friendship salesperson, peddling your presence. It’s one of the most liberating things about adulthood.