You're only supposed to focus on the task at hand, kinda like living in the now. It seems to help a bit and it takes some practice and patience to do, but it does stop the negative thoughts because there aren't any thoughts to begin with. But won't it stop happy thoughts as well? Isn't it natural to have a thought when you see or hear something? Is this how non-sa people behave naturally? Im experimenting with this as we speak. I just don't wanna turn into a zombie.