There is something oddly comforting logging into my first home realm and seeing the same trade troll doing his thing in general chat Hyjal.
I was having difficulty deciding who I wanted to level next, and if I would move them to proudmoore. We are now a level 7 guild, so the leveling bonuses and experience would be useful, but since my main went solo to proudmoore I need to transfer over who I want to level next, and I have half decided on my hunter who was my only 80 left back on my home realm. The rest are all still on BR.
Several attempts at transferring my hunter failed because I had mail in my bags. So I got as far as that transfer screen, and then had to log in to delete mail, but then I would get distracted, and want to play a little, randomly mash buttons and kill things, pat my pet, and consider getting a new one – but decide I am happy to keep Ironjaw Then I got a hair colour change from red to black, and then I would go into an BG, and now I am 1 bar off 81 and still on the same realm.
I still know people on there – and seen the odd name floating around I recognise, but I’m now some random they probably won’t remember on an alt .
It was always my home. I’ve had the most fun, and the most fun raiding on there, I ummed and ahhhed about leaving it the first time, and in hindsight as long as I passed the trial I was on when I left to follow ex guildys I would have seen most of the same content in the end. I got to see 11/12 hardmodes – and multiple attempts on heroic LK, and the ICC Drake, so I guess they are some things to be proud of and I don’t regret that part.
I had always left that one 80 as an anchor back on the home realm but now I think I should be letting go, she will be easier to gear if she’s with my main. She won’t have to level taggless, and the greens she picks up while leveling will make my mains enchanting happy. So many reasons to go, but also so hard to let go of.
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Pugnacious Priest's Warcraft Blog 
I know what you mean. My Home Realm was Garona, I actually have a 16 level Paladin there that was still in guild so I can hop back on and talk to my old guildies.
So I was feeling nostalgic one day, logged on to my Garona Pallie to see who I can find, I said Hi to everyone in guild chat..
No on responded, I got the cold shoulder, little sad but it’s true maybe you can’t go home again.
So later that night I removed my pallie from the guild, and deleted.
I do still have a Warlock there, with some gold though if I ever do want to come back. But I doubt it.
I think eventually you find out… to your real friends, it doesn’t matter what server you’re on.
Sure, you can’t “do” anything. But then again, most guilds aren’t about friendship; when raiders join a new guild, most of the time everyone there is random. Guilds are often sought because of common aspirations and goals — certainly you can become friends because of similar ideals/goals/aspirations afterwards; but lets not lose focus on the main reason for you being there.
Of course, I speak more explicitly of raid guilds, there are definitely social guilds, leveling guilds and all sort of other guilds. (I even know of the rare “gold guilds”).