Since Buffy is where I feel comfy, where I can express myself through, thinking about all the time... BB is mostly about Buffy. So how could I not feel good here. So it mostly brought me comfiness as a home, because Buffy is compared to home in my heart. I really enjoy debates, and I think like the OP said, it brought confidence. My confidence though didn't start from this forum. But I used to be a very shy girl, who took acting classes and then took also a job that required contacting with people, so it brought up my confidence a little. But I still wasn't too brave to say what I think. And that's what BB did to me. Has made my confidence rise way up. I've become out spoken, I say what I think, and don't afraid of it. Because I know not all people would agree with me about stuff, and that's okay. Because I'm not that shy girl anymore, who used to be afraid to speak and be scolded. It has affected me in other areas, inside and outside the net.
Also, and I'm so thankful for that, before I read what other people think about stuff from Buffy, at many topics, I was clueless about many things while watching the show. Now that I read what people's views are, it opened my eyes a little, and enriched my Buffy world so much. I'm talking about all the theories, things I've never even thought about. I feel more smart, Buffy-wise, because of all the opinions here. And it made me love Buffy even more!