Hey now, Manu, I totally get what you're saying. I had a very tight group of friends who all went on tour together all through college (probably 5-8 of us, plus a whole home town crew from one of these guys), and after that we'd try to hook up when shows were local to them but a few years after graduation, less and less were able to join in. I think when you're early in your career it's difficult to take off so much time to go to shows. Then a lot of folks started having kids and their priorities changed and/or they just didn't have the time/money/whatever to go to shows. Then Jerry passed and nobody knew what the hell was going on and some folks never got back on the bus, or didn't even know the bus started running again. I'm still amazed some of my oldest head friends from way back when don't even know about Furthur. It's a little sad to think they're missing all the fun, but my old college room mate is going meet me at a Fall show so that'll be nice.
As for new show friends, we personally don't hang with a crowd but we've ended up meeting a handful of people that we go to certain shows with all the time, but ironically we don't go to any shows in the town where we live with anyone, just solo, and that's fine too. I went to some Dead '04 show, I think it was, alone, and my husband was like "what? you're going by yourself?" and I said, "yeah, I'll be amongst friends, don't worry" and in the end I sat near some cool folks and one dude who was at his first ever show, so I wasn't really a stranger, or alone. You can be strange, for sure, but if you're a deadhead, you're never a stranger at a show. At least that's what I think. Mileage may vary and all that.