'The difficulty lies not in the new ideas, but in escaping from the old ones.' John Maynard Keynes.
How true that is. It is difficult for us to leave behind our old ideas because they are comfortable. Taking on new ideas means being uncomfortable for a while because we are learning to think differently. We can't just go by reflex. But when we have new information it is necessary to make sure that we look at it and modify what we might already think.
In some ways it's like trying to escape the gravity of a planet - it takes a lot of energy. But we have to put that energy in if we want to continue to grow. Without growth we are stagnant, and who wants that?