Is It Easier to Let Go of Pet Theories?

When we have strong views about something and somen we we see a disconfirming piece of evidence that comes in, it's easier to discount the disconfirmance. This is why it's so hard, not just in politics, but in science as well, to let go of pet theories. And you've spent twenty years developing a theory, it's incredibly painful to let that theory go because some new fact just arisen....