Here's an interesting tale of Mulla Nasrudin from Inries Shah's collection of Nasrudin tales:
"How old are you Mulla?"
"But, you said the same last time I asked you, two years ago!"
"Yes, I always stand by what I have said."
Have you ever met anyone who said "That's what I believe and nothing will ever change my mind."?
Have you been impressed by the fact that they always stand by what they have said?
We vilify politicians who change their mind, calling them "flip-floppers." We don't respect people who do this.
But, what's so wrong about re-examining one's beliefs from time to time and changing them in light of new evidence.
The economist John Maynard Keynes is reported to have said: "When the facts change, I change my mind. What do you do?"
He may or may not have said this exact thing, but the sentiment is still a good one. What do you do when the facts change? Do you stand by what you've always said like Nasrudin or do you change your mind?