You have three types of voices in your head: observing, craving, judging. You eat some cake and you notice, this cake is moist. This is your observing voice. Then you think, where can I get more of this delicious cake? This is your craving voice. Three slices of cake later, you conclude I ate too much cake, which means I’m a weak person. This is your judging voice.
The observing voice deals with raw sensory data in the present moment. It keeps you plugged into the Here and Now of your daily life. The other two voices tend to lead you down various rabbit holes. When you get lost in your craving or judging voice, your actual experience gets watered down. In Zen it is said: The finger pointing at the moon is not the moon. Thinking about eating cake is not the same thing as eating cake. Mindfulness means allowing yourself to simply be in the moment, noticing its various sensations–however pleasant or unpleasant. By paying more and more attention to What Is, you spend less time worrying about What Isn’t.