I'm always so surprised when people accuse me of having changed my mind. Almost like it's a negative thing.

Something to the effect of, well that's not what you used to think...

No duh, I have more information about a subject matter and have changed my views accordingly in response to that new information. That's what you should do.

I feel like they believe that sticking to your guns is a virtue even when the facts say otherwise. We have a word for that it's called stubborn

It's ridiculous, really. Imagine where we would be as a society if we never changed our minds about anything. We'd still be grunting in trees befuddled by fire.