A familiar friendship can need a new routine when ordinary life changes around it.

Friendships are held together by practical things as much as by affection: the shared commute, the same street, the class you both attended, the standing Thursday. When the practical thing ends, people often read the drop in contact as a change in feeling, and neither of them says so. The affection is usually fine. It is the infrastructure that stopped.

Rather than waiting for the old rhythm to return, build a small new one that fits the lives you have now. A monthly call, a walk, a standing date. Say plainly that you would like to keep this.