The feeling of closeness, camaraderie, friendship with like minded people you could trust.
Haven't read all the replies, but the last part of this sentence stood out. "...people you could trust"
Yes, there was closeness (within in some cliques), camaraderie and friendship with like minded people. But that's true in most social situations, whether it's church, school, work, the neighborhood bar.
The last part is debatable. Trust. You can't trust most people in the KH. The ones that aren't always ratting you out to elders for every little infraction are either jealous of anything you do or have, or if they're the haves, instead of the havenots, they rub it in your face.
Not true of all JWs, but common enough that most dubs have to watch what they say, watch what they do, who sees them in public, etc etc.
I learned to keep my life so private that most people really never knew me. I couldn't trust em. And when I slipped up and trusted someone, it lead to my undoing. I had friends, but I learned somehow to keep most of them at arm's length.
These people are not your friends. The fact that since you left, no matter the circumstance, and they are no longer your friends proves that.