There is an area of the human brain called "Broca's Region" that is constantly anticipating what is about to happen. When what is anticipated occurs, it gets discounted. This is beneficial for the mind to do in order to conserve resources, and not be constantly using it's energy when it doesn't need to. The equation in the mind becomes: predictable = discounted. Or maybe even: predicable = boring. If you have kids, or are dating, it's good to keep in mind that being boring and predictable is almost a sin.
But back to the mind thing. It's like one of Dad's old jokes. We all know the first few words of dad, or grandpa's overly used and overly told jokes. Even from the first word spoken, certain people's eyes in the family begin to roll. Because we allll know what's coming. Or it's like when you leave the house your mom/dad/wife/husband etc... will say "Now make sure you drive safe" We expect it, and when what we anticipate is spoken or happens, part of the mind tends to discount it, and doesn't really listen. "yeah yeah yeah" is what this part of the brain could be nicknamed.
I think this may relate to some of our blindness of mind when it comes to the Gospel. Especially the scriptures. We gloss over things all the time. For too long we have put the Book of Mormon INTO our own rigid structure rather than let the book INFORM us. The more we hear it, the more the mind says "yeah yeah yeah", and skips it. I think this can happen especially for life long members. It has for me anyway. We may have heard the words and stories so many times we think we know who and what the words are referring to, and therefore the mind either discounts it, or we miss the plainness of what is actually said.