Someone goes into a grocery store, and says he wants to buy an egg. Immediately, as if he just changed his mind, asks for 9 further eggs.
The conversation can go like this:
I would like an egg, please... you know what, give me nine more.
The grocer is a little bit baffled, but gives him the ten eggs.
The question: what was the reason why the buyer used this weird manner of acquiring ten eggs?
This is not a classical lateral thinking puzzle, so there are no secret agent code words, alternate realities or epic plotlines.
This situation not only can happen, but I know someone who did buy eggs like this, and I've heard at least one other story of this happening.
This puzzle might be unfair for those who don't know the cultural background. It is solvable even if you don't, so you can arrive to the solution and find it fairly plausible even without knowing the specific cultural background / specific location where it happened, but if you know it, the answer will be very obvious.
Somewhat stronger spoilers:
I quoted what he might be saying instead of leaving you just with the first paragraph, which described the same scene. However, the use of the words the buyer said might help you a lot.
The conversation is not taking place in English. You can come to a solution without identifying (or knowing anything at all about) the specific language and without knowing any language at all besides English, but knowing it would make the whole story a lot more funny and the answer a lot more obvious.
The guy who originally told me this story, did, during an earlier shopping, try to buy a number of eggs directly ("I would like x eggs, please") and got himself embarrassed. After everyone around laughed, next time around he resorted to something different.