About a decade ago, I was actually playing in a game for once instead of running it, and I was playing the group's thief. The background of the group (big one, too: 8 players) was my character and one of my buddies were playing elfs, so... we were brothers. the group's half-elf was our cousin. Me and my brother knew the rest of the group only vaguely through our cousin, so I had no real attachment to them per se.
So, We're doing some mission/quest/what-have-you for some lord muckety-muck merchant, escorting a caravan from Point A to Point B. Whackiness ensues and the thing gets hijacked and we have to go rescue it all, which we manage to do, and score more goodies in the process.
We get into town, and get our reward and whatnot, and there's loads of loot to be turned into the local currency or something similar... and since half the group has stuff to do, me, my brother, my cousin and the biggest scariest fighter in the group are given the task to go change everything over and come back to the inn we're staying at later and divide up our loot.
So, on the way to the 'bank' I guess you could call it, I spot a bar and pull everyone inside with the promise of buying them a round, because "I have a proposition for you guys."
Said proposition was this: " Here's what I'm thinking, guys. We could take the money we're getting, and divide it up evenly by eight and give everyone their share, or... we do things a better way. I'm proposing we divide it up by twelve, and everyone gets one share, but the four of us, because we're the ones putting our safety at risk here, carrying all this loot around, get a second share. It's only fair, I think. Plus, I mean, they aren't here. If they really cared about just how much we have, they'd be here with us. Again, this is entirely in the interest of fairness, after all."
As I say this, the rest of the guys around the table look at me, mouths agape, shocked that I could say such a thing.
Jaws really hit the floor when my three companions all thought it over for a bit and... completely agreed with me.
So, for the rest of the campaign, whenever I'd say "I've got a proposition for everyone..." everyone'd groan or just outright refuse to listen to me.
When playing the thief in a group, I always do fun things like have the GM write down on a note what's in a chest or locker or something I've broken into, so I get to see it before anyone else. I wouldn't always tell everyone everything, either.
One fun time, I popped open a locked strongbox and peeked inside, to reveal it had a dozen gemstones inside. When everyone asked me what I saw, I responded: "Looks like eight or so gems! One for each of us! Awesome!"
Again, as time progressed, and I'd unlock something and they'd ask what I found and I'd tell them, the usual response was: "In our math, or yours?"
I always took playing a thief or a rogue type very seriously, in case you couldn't tell.
Years afterward, we were all reunited for the wedding of one of the guys, reminiscing and joking and reliving old times, and the stories of my elven thief came up, and one of my friends' other guests who wasn't in on that campaign asked me why I did that sort of thing, and I told him:
"If you're playing the group's thief, and you either don't have more experience coming in from thievery, or more money than most of the guys in the group, you're not really playing a thief correctly, in my mind."
'At two minutes to eleven, opposite the South African Brigade, at the eastern-most point reached by the British armies, a German machine-gunner, after firing off a belt without pause, was seen to stand up beside his weapon, take off his helmet, bow, and then slowly walk to the rear.' -John Buchan
I can't help but think that every time something is proven, a little bit of the magic of the world dies.