I love this piece of advice. People tell us all the time that if we want to achieve our goals, we have to tell them to everyone. By letting others know about it, we would supposedly be more motivated to achieve them since we praised it and are expected to come up with some proof of accomplishing it. I recently came to the opposite idea you mention here, in "The Little Book of Talent" by Daniel Coyle, where he suggests keeping your big goals secret. As you said, telling your goals might fool your brain into thinking it's already accomplished. So, I'm working on keeping my mouth shut :D