I like to think I have a solid, logical understanding of the world. I like to think I can hold my own on debates and have a good - albeit somewhat fuzzy - understanding of my own views. But occasionally some whacko comes along, enticing me with their unfounded, radical, sometimes morally grey ideas and I can't help but say, "Well, when you put it that way..." This happens a lot especially in areas that I'm not too well-versed in. I can't test their facts. So if they present their arguments in a compelling and logically sound way, I can't help but believe them a little. They can never fully persuade me but for a split second, they can catch me off-guard and doubt my own opinions/moral integrity ("Wait, did I just admit to thinking child porn's okay?!").
Of course this process is entirely internal; outside I may still be arguing my point relentlessly. It's just a bit unsettling to think that someone can mould me like putty if they do it the right way... just because my mind is wondering, "What if?"