I can fold my arms, but....

I don't know about you, but when I have one of those chocolates that come wrapped in foil, I just have to smooth the foil out and then fold it and fold it again and so on.  And this always reminds me of that old conundrum - how many times can you fold a piece of paper in half?  It used to be said that however big a piece you started with, you wouldn't be able to fold it in half more than seven times.  The problem is not the size - it's the thickness.  Each time you fold it, it becomes twice as thick so after seven folds it's 128 times as thick as originally and this is what will defeat you.  Actually a smart young lady from California worked out that if you folded a long thin piece of paper end to end (think unrolled toilet roll) you could do better than that, and she actually achieved 12 folds!