The umbrella left behind at a party can become an excuse for one more ordinary visit.

Friendships need pretexts more than they need occasions. Something forgotten in a hallway creates a small legitimate reason to see someone again without having to arrange anything, propose anything, or admit that you would like to. Adults are oddly dependent on excuses like this, since the invitation with no cover story feels exposing. The returned object is a way of saying come round that does not have to be said.

Use the pretexts you have. Return the thing in person, drop off the book, deliver the borrowed dish. And when someone manufactures a reason to see you, take it at face value and say yes.