Megan, I'm just like you with not having that "off" switch. Even when I was a little kid, I wanted to keep eating, even when the rest of the family was finished with a meal. It wasn't emotional eating; I was genuinely still hungry. I totally believe I was born that way and so are a lot of other people who struggle with weight.
So like you, I had to learn portion sizes and eat with my brain, not my stomach as a guide. There are plenty of times that I can finish a planned meal and still feel just as hungry as when I started, but I know with my head that I ate a reasonable portion of food so I stop. I'll never be able to be an intuitive eater -- unless I want to be morbidly obese again!
I agree with the article's conclusion that obesity is multifaceted and we're only just beginning to understand the causes. Thanks for posting it!