You meet new people every single day, even though you aren’t formally introduced. You stand with them in elevators and walk by them on sidewalks. They serve you at restaurants and get in your way at the fountain drinks. They sit with you in traffic and cut you off while talking on their phones. Every day you pass potential friends or partners, maybe someone you could help or someone who could help you. They see you or you see them or sometimes both, but only for a moment and then they’re forgotten. Even though you miss these opportunities, you don’t care. You don’t even notice. You don’t mind that they remain strangers because you didn’t know them anyway and you’ll likely never see them again.

Every so often, a person emerges from the shadows of anonymity — a friend introduces you to her friend, or the person beside you strikes up a conversation, or some other happenstance. If the conversation remains casual, you perform the expected niceties and small talk that allow you to get from point A to point B as pleasantly as possible. Sometimes the conversation deepens and hooks your attention, but even then you usually don’t feel the need to apply much effort. You’re not invested in the outcome so you’re not self-conscious. And if the conversation is interrupted or ends awkwardly, you don’t mind. After a brief moment of familiarity, the person becomes a stranger once again.

But once in a while something peculiar happens. From this huge pool of unknown strangers and temporary connections, you meet someone with whom, for whatever reason, you want to have a better relationship. Maybe it’s a coworker you respect and you’d like reciprocation. Maybe it’s your future mother-in-law and you want her approval. Or maybe it’s just plain old physical attraction. Whatever the case, you care what that person thinks about you and how they act toward you. You’re invested in the outcome, so you’re compelled to make an effort. You decide, perhaps subconsciously, to try.

What if the person just isn’t giving you the time of day? What if they aren’t reciprocating your effort or your interest? Worst of all, what if it feels impossible to not care about someone who doesn’t seem to care about you? Depending on your disposition, you may feel inadequate or indignant. But when those feelings pass, you’re left in the agonizing position of figuring out what to do with all your unrequited care. What’s worked for me, in relationships of all kinds, is a simple idea that was difficult to learn:

Meet in the middle.

If you give a relationship your best effort — if you go to “the middle” — then you’ve done your part. That’s all you can expect. If the other person doesn’t make an effort, knowing why isn’t as important as knowing that you tried. Now it’s their turn, and all you can do is wait, patiently, at the middle. But this isn’t a stop-your-world type of waiting. You’re not sitting there thinking about the person, emotionally invested in their actions. Your life goes on.

Just to be clear, here’s what I’m not saying: I’m not saying you should always wait for others to make the first move. (Take chances. Break the ice.) I’m not saying you should always expect something in return. (Give more than you get. You can scale back later.) I’m not saying that the solution to everything is compromise. (“The middle” is about relative effort, not dealmaking.) And I’m not saying you should give up on people easily. (To misquote John Lennon: Give people a chance.)

I am saying you should challenge your instincts. And I am saying you should be selective about the people in whom you invest time and energy.

It’s tempting to go past the middle, overcompensating for another person’s lack of effort with too much effort on your part, especially when you want so much for a relationship to work. But chances are, the other person isn’t thinking about your relationship like you. Or perhaps they just don’t care as much as you. Instead of taking that personally, take it as a warning signal — a steady blinking yellow light — reminding you to pause and consider whether this person may be wrong for you, for now. The right people are those who, without having to try, care. And because they care, they try anyway.

In a way, while waiting at the middle for the other person to get there, they become a stranger again — one of the billions of people in the world whom you don’t yet care to know. Who knows: maybe, like strangers sometimes do, they’ll surprise you. But if they don’t, you’ll be too busy living your life to notice.