Chinese Finger Trap Relationships

Yesterday while texting with a buddy from China I made a tiny obscure joke I wasn't sure he'd remember and pick up on, but he got the joke and I was *tickled pink* he still remembered, appreciated and understood with no explanation needed. Our shorthand is so very short. I adore this guy in a way different from guys I've met in America and I think it has everything to do with the crap and inconvenience and hardships we battled and two years later I wonder: how long will it be until I don't feel this attachment? I feel similar special attachments to other friends I knew there and sometimes it's like I'm trapped in this tension that will never be assuaged because we'll never live that life again. And if I always feel it, is that okay? To just live with that? I get attached to people, but as a human being I don't think that's anything to apologize for. Aren't we supposed to? (However, when someone dogs me or is constantly "too busy"...