I'm on the train back up to London, queueing at the buffet car. Taking out my wallet, I hear a vague rattling sound, but ignore it.
YOUTH: Someone's dropped a dice!
ME: Oh, that's me.
He hands it back, and as thanks, I decide not to point out that it's a 'die' singular, not a 'dice', that's just stupid.
YOUTH: (suspicious) That's a weird thing to have in your pocket.
Now I happen to believe the contents of an English gentleman's pockets are his own business, and I don't much like the tone of his voice, but fair's fair, he did hand back my die.
ME: We've set up a high stakes gambling section in the first class bit.
YOUTH: NO WAY.
ME: Yes, it's all getting rather tense, so I've popped out for tea.
YOUTH: THAT'S AMAZING!
Quite long pause. I realise this has backfired rather.
ME: Um, sorry, no, that was a joke. I'm just into roleplaying game stuff but most of my stuff's in Cornwall. I thought I'd bring some dice up with me this time.
ME: I suppose it could have been more embarrassing. It could have been a goblin.
He stares at me. I have quite literally blown his mind.
I take my coffee and head back to my seat. The youth's eyes bore into my back the whole way.