The confident person at the party isn’t the one telling stories. It’s the one who doesn’t need to.

Performing is work, and work implies something at stake. The person holding the room often needs the room, while the person who is comfortable can sit in a corner talking to one person and lose nothing by it. Ease is quieter than confidence usually looks, which is why it gets missed. Nobody is impressed by it in the moment and everybody remembers it.

At the next thing you go to, try aiming for one real conversation rather than a good impression. Ask questions, listen to the answers, let the silences happen. Leaving early is fine too, and having nothing to prove shows more than any story would.