The provocative bigfoot ponders why being open minded might be an impediment to learning. He's clearly trying to provoke me, but I'm too weak to resist.
Human learning does include a good amount of filtering. The distinction he has missed, though, is that closing our mind to new ideas is not the right sort of filtering. Rather, forgetting is the critical skill.
Our mind is on a neverending quest to produce the best understanding of the world possible (the better to foresee problems, preparing to overcome them and live to perpetuate the species.) It can only do this by remaining open minded, taking in as many thought patterns as possible. After all, we evolved as a social animal not only for safety in numbers; our fellow human's ideas might offer us shortcuts in understanding the world we live in (thus our species presently advances at an amazing clip, despite almost no recent changes to the physical structure of the brain).
One cannot go about accepting every communicated idea, of course. So, we attempt to fit in each new one with our present understanding, and if it just doesn't work, we discard it. When we do this consciously, we call it reason, otherwise we call it intuition. It is dangerous, though, to perform this filtering too early, or even actively prevent "polluting" our brain with worldviews that differ from our current understanding.
That is why I still consider the thoughts of the political authors who are typically very far right or left of my own thinking. If I started listening only to those who navigate by the same maps, I'd be forfeiting my chance to explore better vantage points, or at least strengthen my existing position.
Pre-filtering ideas before I even consider them, citing the "quality of information" etches my map into stone. This might make some feel safe and secure, but it means my journey is over and I might as well set up camp, and just sit watching sitcoms for the remainder life.