What have you changed your mind about, and why?

After several days away from my computer, I checked out my news reader and came across another interesting post from the TedTalks - What have you changed your mind about and why? For our project I was interested in what Wired mag's Editor-in-Chief Chris Andersen had to say about carbon and climate change and then I saw the post from Tim O'Reilly on why he's changed his thinking about social media.