The difference is mostly due to the fact that Cole hasn't really met any mind-readers that he can use by comparison. What he knows, he just knows about himself.

Still, Yuya doesn't want him to say things, so he won't. "I can do so. Keep it close, try not to tell. I did it with Ranier, I can do it with you."

Though honestly, Cole doesn't see why. Yuya knows about Zarc. Other people know about Zarc. Why is he keeping it a secret?