When I first moved to Taiwan and was just getting a handle on Chinese, I asked a waiter "請給我一個筷子" - not yet being familiar with proper measure words.

The waiter (who had a bit of a sense of humor) brought me exactly ONE chopstick. I laughed and repeated 請給我另一個筷子 (Please give me another chopstick) and he brought out another one.

Of course later my friend told me that I should have used 雙 to indicate I wanted a "pair" of chopsticks.