Reminds me of the juvenile remarks of a child:
"I know a secret but you're not allowed to know!"
"Guess what?" "What?" *giggles*"I can't tell you."
And my favorite: "I know something you don't know!"
Seriously, is an announcement which announces that something can't be announced suppose to create suspense? All it does is sound like braying to me. Go home Brennos, you're drunk. Sleep it off, buddy.