An interest becomes easier to pursue when there are other people expecting to do it with you. A club turns that expectation into an arrangement. Members return for an activity, contribute to keeping it going, and develop relationships through doing something together.
A club can be informal or have explicit membership and governance rules. The structure should make participation dependable without demanding more administration than the activity can sustain.
Belonging through doing
Imagine people who enjoy observing birds forming a local club. A regular walk creates a rhythm; experienced members help beginners notice what they would miss; shared records preserve what the group learns. Someone coordinates the route, and someone else can take over when they are unavailable.
Membership gives access and can also define a boundary. Dues may fund equipment while excluding people with little spare money. Familiar jokes and assumed knowledge can make a formally open club feel closed. Newcomers need a manageable first step, not an immediate demand to behave like longstanding members.
The activity also protects the relationship from becoming entirely abstract. People have something to return to even when conversation is initially awkward. Over time the club may provide friendship, practical support, or opportunities beyond its original subject, but its continuing life depends on making the shared activity worth doing.