Theoretical distortion of reality

When you have a theory or rationale for how something works you become quite blind for what is actually happening, as you try to view things in a way that make them fit into your assumptions. You're attentive to what fits and ignore what doesn't fit into your theory. So the theory is futher approved and strengthened. Evidence that it is wrong can be pretty damaging after you've been working with a theory for a while. You have to redo all your thought experiments and may land with the nose on the floor. It makes you actually sad to recognize how wrongly you interpreted reality, because of your allure of knowing a theory in which things fitted so nicely. And if you acted upon your assumtpions you might have quite a lot of consequences to live with now.