You should keep an open mind about most things. Yet, as The Old People like to clarify, "Not so open that your brains fall out".
How can you tell the difference?
You don't need to be open-minded to every obviously bad idea: toward murder, rape, theft, kidnapping or other acts of archation. Being open-minded to these is a sign that your brains have fallen out. Closed-mindedness to things of this sort is wisdom.
But pretty much everything else is a good topic to keep your mind open on. You never know when someone might have a good perspective you never considered before. You might even discover you were wrong.
