A secret can be kept by one person, several people or even a large group of people. It is a secret as long as it is exclusive to certain people. For example, most national governments have secrets that are kept from other nations. Many clubs or societies have secrets that are kept from outsiders to those groups. Married people usually have secrets that only the two of them know about. It occurred to me that you might be asking if the sentence is grammatically correct. It is! I also agree with Pat. I hadn't thought of the statement in that context.

The statement alludes to people not being able to keep a secret. If two people know a secret, one of them is bound to tell someone else, and therefore the secret is no longer a secret. Basically it says, if you have a secret don't tell anyone!! :))))))))

I'm the only one that know the answer to that. an I'm not telling.

I can't tell you answer, I am keeping a secret here.

Yes