To become really aware of your fullness, it takes a lot of practice. By using the fullness discover scale you'll gain more understanding of the meals that keep you full longer and the meals that have you looking for more food an hour later. Paying attention to your fullness and practicing awareness around it  - you'll learn how to get to your endpoint of eating - aka the last bite threshold. It's the point where you notice that just one more bite of food will likely be your stopping point for a comfortable satiety level. As you know - you may choose to eat past fullness but it's a practice in learning exactly how much food your body needs to be comfortably full. Try the last bite threshold experiment and let me know how it goes.