This. And you know there are people you trust very strongly with secrets, but you never know under what circumstances they might reveal it to someone else.

I learned from a very young age to keep information to myself because my mother is incapable of keeping secrets to the point of defiance. Nothing I or my siblings told her was kept secret, we all knew about each others' business in short order. She has always insisted this is a good thing and secrets are bad (and yes, she has no secrets either...), but I know now in hindsight why this was an awful policy.

So some of us learned to never say anything.