This is a subject that can be attacked from many different directions.
One is a bit of a skeptical cliche, but that doesn't make it any less true: "There is so much that is amazing in the real world to be awestruck about, who needs to make up magical absurdities to believe and wonder upon?" Or something to that effect. The same idea has been said by so many people - I've been in the room to hear each of the JREF Presidents (James Randi & Phil Plait) say it - in so many different but contextually similar ways - that it's nearly tiresome. But as I said - it is still true nonetheless.
Another aspect, which I'd like to go into a bit with the aid of a current example from my own experience, is that I have found a shift in my thinking as my skepticism has coalesced towards a tighter, more consistent form.
Despite having been on a clear road towards skepticism throughout my life, it would be an absolute lie to claim that I've never held to one degree or another irrational thoughts. There have been any number of things - personal sacred cows - that, despite having developed a reasonably good instinctive bedrock of critical thinking, still slipped past the goalie.
My initial reaction to some of these would best be described as outright denial. For me the best example would be echinacea. The suggestion that it might not have an evidence based effect was met by anger. Even when I looked at the arguments it took a long time for me to accept. Even when I DID accept I kept a bottle of echinacea in my cabinet for months. My symbolic acceptance of the process od skeptical thinking - which had in fact happened long before by degrees - was when I flushed the contents of the bottle down the toilet, rather unceremoniously but still fully aware of the symbolic implications.
Other dawnings of awareness manifested in different ways. The revelation that there is a vast segment of chiropractic medicine that is a total sham? Well I'd used a chiropractor - thus that meant a certain amount of admitting my own error - so that wasn't so comfy. I had been to a Chiroprator who practiced primarily evidence based methods - that got in the way a bit. But gradually as I listened to the arguments I came to see the complete and obvious load of shit the extreme end of the profession is. By now I find it completely absurd that I ever even considered it possible that it was real. "You can cure my eczema by fucking with my back....? Really, now." But that tiny bit of physio-therapy under another name that is part of the profession sure lent the rest of it credibility.
Flight 93. I was never really a 9/11 conspiracy theorist. But it struck me as being totally possible that the US government shot down their own plane. In fact, it actually still makes pretty good sense on the surface. Hijacked planes were flown into each of the WTC towers and the Pentagon; a fourth plane was not responding and was on a course for Washington D.C. - very possibly with the White House as the target. Would shooting down that plane while it was still over Pensylvannia farmland make sense? Would sacrificing about 40 people for an untold number on the ground (they could evacuate any number of probable targets, but still not know for sure what the actual target was until moments before hitting - assuming the hijackers were accurate) be morally defensible? Yes. But because it would be morally defensible does not mean that it is something you would want to defend. I was never a fan of the Bush Administration, but I couldn't blame them for wanting to keep it under wraps that they had willfully killed American citizens by shooting down United 93. And this story, thus far, fits with the rest of the day without having to invoke a conspiracy greater than "They hid the one thing that would have endangered their chances of re-election." No inside job necessary. Very little nefarious plotting required. Anyone who made claims along those lines - the 9/11 truthers - pissed me off from their first appearance.
When I was first presented with a good argument that Flight 93 played out as we have been told by the media, my response was to cry (quite literally) "Bullshit!" But it wouldn't last. I recognized good logic when I saw it. I admit that even today I still have an emotional instinct to want my old way of thinking on this matter to prove correct, but I know that the chances are diminishingly small.
Which brings me to the change.
Just today this credulous article about hoop snakes was posted on the Monster Talk discussion board.
I recall reading about hoop snakes in Ripley's Believe it or Not as a kid, and that is about how far they penetrated my conscious. I hadn't thought about them again since. More to the point - I never had the opportunity to discount them as a rational thinker.
Discovering today that they are and were more than likely an absolute fabrication was a delight. Rather than be irate about it (admittedly this is a pretty inconsequential item), my reaction was more along the lines of "Oh cool! Something else I had an underlying acceptance of is bunk!" I suspect that part of my response comes from knowing that there is and will continue to be less and less opportunity to feel that way as my life goes on. I expect that there is little to nothing left that I hold dear to that could be debunked to my chagrin.
Beyond the emotional trauma of having a sacred cow destroyed I think there is another factor at work. I think that the wonders of the real world hold more appeal to me now that the imaginary constructs. The act of making that discovery is a active piece of real-world wonder.
Which is not to say that I won't like a good science fiction movie. That is entirely different. The word 'fiction' in the genre title is key. I know and accept I'm being lied to as part of the cultural exchange of ideas. Whereas a film like "The Haunting in Conneticut" which claims to be a true story just makes my skeptical blood curdle. I suppose there is an analogy there to magicians. Experts at sleight of hand like Jamy Ian Swiss or Ricky Jay who never claim to be anything more than guys who are really good at manipulating playing cards are awesome, but Sylvia Browne who is a charlatan and a liar who uses well-known trickery to make it appear that she is in touch with the dead and who willfully bilks people out of a fuck-ton of money infuriate me beyond belief.