After school ends, the hallway that made friendships easy is gone. You have to build your own hallways.

School friendships are largely a product of architecture. The same corridor, the same timetable, the same hundred people repeatedly in your path: that proximity did most of the work, and you never had to arrange any of it. Once it goes, nothing replaces it automatically, and people mistake that for having got worse at friendship.

Make one recurring thing and protect it: a pickup game, a Wednesday coffee, a shared ride, a standing dinner. It has to repeat, because repetition is what the corridor was doing. Start it yourself rather than waiting to be included.