They aren’t kept secret.
President Wilson had a stroke. It was kept a secret.
Silk was kept secret b/c of its value
originally maps were incredibly expensive to make and took considerable time. To recreate these was also vastly expensive. therefore when early explorers had maps which they made as they went along these were a valuable item as they were frequently the only reference to how toget to somewhere
Secrets should be kept secret because if they were not, everyone would know it. If everyone knew your secret, then you probably wouldn't be too happy. And a secret would not be secret then.
Best Kept Secret - song - was created on 2010-09-03.
A best-kept secret is a significant fact or characteristic about something or someone which is not particularly well-known.
The Best Kept Secret - Alphrisk album - was created in 2004-10.
Nobody knows. It's a secret.
In the kitchen...
B-Ball's Best Kept Secret was created on 1994-11-15.
It was a kept a secret because it was a meeting to discuss what they were going to do to the Jews and the " The Final Solution " was a code name for the extermination of the Jews
They knew they were the first to learn how to work iron and kept it secret.