Less say I have a secret and I tell everyone on this planet, one by one and covertly. Everybody knows the secret but only I know that, the rest of the population think it's just me and them. Is it still a secret?

The original secret isn't a secret anymore but if you dont tell everyone that everyone knows then you still technically have a secret but it isnt the original secret so yes and no?

But everyone thinks that only two people (they and I) know and nobody tells. So the entire population knows something, but they don't? I don't know that's why I'm asking, it just popped into my head haha.

But you see thats also saying that they still keep that they know a secret so if each person tells another person they would soon find out that everyone knows therefore neither thing is really a secret anymore