Brain_fullTo the right is one of my favorite Far Side cartoons. I also like this short story:

A university professor went to visit a famous Zen master. While the master quietly served tea, the professor talked about Zen. The master poured the visitor’s cup to the brim, and then kept pouring. The professor watched the overflowing cup until he could no longer restrain himself. "It’s overfull! No more will go in!" the professor blurted. "You are like this cup," the master replied, "How can I show you Zen unless you first empty your cup."

Sometimes, unlearning operates in the same way. First, you must empty  your brain.