If a map could show missed encounters, the busiest intersections might be invisible on every road map.

The most significant thing about a place can be something that failed to happen there. The corner where you nearly met someone, the street you did not turn down, would make a map of enormous importance and total invisibility. Roads record traffic; they cannot record the encounters that did not occur.

Rather than mourning that, use it as an argument for slightly more contact. Say the thing to the person, take the introduction, follow up on the conversation that trailed off. Most of the encounters that shaped your life were one small action away from not happening, which suggests the small actions are worth making.