You’ll outgrow some friends before you find new ones. That gap feels lonely. It’s a hallway, not a room.

There is a stretch between leaving something behind and arriving somewhere new where you have neither, and it is genuinely lonely. Growing apart is not a betrayal by either side; you changed at different rates and the overlap got smaller. The loneliness is not evidence that something is wrong with you.

Get yourself where new people are regularly, a club, a team, a job, a class you chose, because friendships come from repeated proximity more than from effort. Keep the old ones you still like without forcing them. And on the bad evenings, telling somebody you are lonely is a far more common sentence than it sounds.