I can't tell you how many times I've inadvertently blown a secret just because I didn't know it was a secret. It's to the point where as soon as anyone asks me, "Hey, can I tell you something?" I ask for these details.
People think other people should always be able to tell. Some of us can't. I don't just not read minds. I also don't (usually) read social cues.
There's definitely an audience for this. It just isn't you!