I've only had the game a week or so, REALLY enjoying it so far.
The server was down and I updated the game (via files on macbook pro) and started up a single player, I'm still learning the game and often do daft things.
Anyway, long story short, found a seriously epic cave, tonnes of stuff, full stacks of iron / gold / that red stuff / blue things / 20 odd diamonds. Epic. Got lost
Just spent the best part of two hole hours trying to find a way out, dig up, spend hours digging up, hit dirt, no tools, feeling annoyed I'll never get back to my house ect ect, finally day light. Come up.... 10 or so blocks from my steps
Great feeling and immense buzz from that, not had that in a long time in a game.