I've always enjoyed walking into the middle of conversations and trying to figure out what they're about. Especially when the terms people are using are general enough that there are several different possible subjects. I believe xkcd.com has put together a few comics about that.
Today one of my coworkers was dining out at Fire and Ice with her husband. Fire and Ice is a restaurant where you pay a cover charge and eat all you want. They have all kinds of raw food (meat, veggies noodles and a salad bar) and you grab what you want to eat and put it in a bowl, along with some sauce. You take the bowl to a communal cooking area-a circle shaped griddle with cooks standing around it. The cook takes your bowl of stuff and dumps it on the griddle and cooks it and returns it to your bowl. You take it back to your table, eat it and then go back for more.
I was attempting to give my friend and her husband a few tips on the best way to go about this (make sure you've got enough stuff in your bowl, get a bowl full of stuff to be cooked and a salad at the same time so that you spend as much time eating as you do waiting for your stuff to be cooked etc.)
I was saying "When you get there don't be afraid to use your elbows--it's a big crowd and then some guy comes up to you and grabs all your stuff and.." When I was interrupted by another coworker.
"That sounds horrible." She said. "What is this--arrival at the Concentration Camp?" We explained that no, it was dining out at Fire and Ice and then it occurred to me that we could have just as easily been discussing checking baggage at Logan Airport. Both alternate scenarios involve large crowds where someone comes up and grabs all your stuff.
I've been laughing about it ever since. No one else seems to get it though.