I'm DN4 originally, but live in London now. Welcome! Here's a few things you'll need to know:
If you're optimistic about the Blades, avoid the shoutbox between 3 and 5 on matchdays and prepare to be called a clapper.
If you're not optimistic about the Blades, you'll fit right in mostly, although expect to be called a doom merchant or something like that but you'll find a guaranteed friend in
metalblade.
Prepare for 1,000 threads a week from now on about Ched Evans.
Pick a scapegoat - you can't have Montgomery because he's left and therefore doesn't actually influence team affairs, but plenty of people have replaced him with Baxter.
Don't take it too seriously.
And above all, be prepared for the sky to have fallen in, the Earth to have ended and there to be no God if we have lost at home.
Enjoy!