Oliver Wendell Holme said something similar: “A mind that is stretched by a new experience can never go back to its old dimensions." -New thoughts, new ideas can permanently change our minds. Our thought process is different, once we have a new idea with which to play. Our horizons of ‘possible’ have been moved, and there are now new spaces to explore.
As we hear new ideas, our minds are often drawn there. To explore this new open space is almost an imperative. We may not always find this new space useful, but we still notice all that new space.
Even those ideas we dislike leave our mind stretched, if only in our attempts to refute or disprove the new idea. Our minds are never going to return to the size they were before. And that is the point.