Your calendar was full at 21 and empty at 26 for a reason MIT discovered in 1950.
Researchers studied a housing complex called Westgate and found friendship was predicted by one variable above everything else: physical distance between front doors. Students living near stairwells and mailboxes made the most friends. Shared interests, values, personality? All downstream of foot traffic. They named it the propinquity effect.
Researcher Rebecca Adams later distilled friendship formation into three conditions: proximity, repeated unplanned interactions, and settings where people let their guard down. A college campus delivers all three automatically, dozens of hours a week of engineered collisions. Adult life delivers zero by default.
That's the entire mechanism behind days blending together. Your brain registers novelty from unplanned human contact. Remove the collisions and time loses its texture.
The fix is repetition. One dinner party changes nothing. The same gym class, same coffee shop, same pickup game at the same time every week rebuilds the structure school gave you for free. Friendship grows from accumulated accidental contact, so frequency wins.
College handed you a collision machine. Adults who stay social just rebuilt one.
Gen Z realizing one of the biggest shocks after college is that life no longer happens around you.
In school, friends, events, relationships, and opportunities are built into your environment.
As an adult, if you don't actively create a social life, weeks can turn into months surprisingly fast.