What's up with this girl?

So yesterday I was talking with one of my female friends, who I am voluntarily just friends with. During the conversation, she mentioned that she was single and looking for a casual kind of relationship, at which point I said that I was also available. Here's what's got me confused: the next thing out of her mouth was literally "You're a nice guy, and you're attractive and funny and smart and you're the kind of guy I'm looking for, but I don't want to go out with you." What the h**l? I'm seriously confused here is it me specifically, or what?