You're treating knowledge as a binary, which it isn't. My way deals more gracefully with thinking you know and being wrong: since you always say what you know, but allow that it may be just a guess, you're always prepared to back off and rethink it. But if you treat knowledge as yes/no, then when you think you know and you say that "yes", you're ready to go full-steam ahead and you're less likely to turn back, since you already "decided" that "I don't know" wasn't the answer.