Power of not knowing

To continue my question from last article, I would like to show you simple scene:

Risky way

You can asses that you colleague speaks same "klingon" language and tell him about all ups and downs of things you have to do to achieve that goal. Of course you know it can be done, but with some cost. Let's say one month.

Better way

Or better leave "klingonish" for yourself and tell him information that has value from his point of view.

So. What's you opinion?