People often ask what meditation is like, or what they're supposed to be experiencing or doing. During my retreat, I thought of a few analogies. I just remembered one of them, and I thought I'd share it briefly.
Have you ever had the experience while reading where you have to re-read a sentence (or whole paragraph) because you weren't really paying attention for a few seconds? Maybe your mind wandered off to what you're going to eat for dinner, or maybe you were just thinking about the last paragraph. The point at which you realize that you've been distracted is where you typically regain mindfulness. Mindfulness is about knowing where your mind is right now.
Had you actively chosen to think about something else while reading, you wouldn't have had to re-read the sentence, because you would have known to stop reading. There would be no sense of "oh crap, where was I?" In colloquial terms, perhaps consciously choosing to think of something else could be considered "distraction," but in the context of meditation, it is not (necessarily). It is said that "when there is mindfulness, there is meditation; when there is no mindfulness, there is no meditation."
When beginning meditation, it is often suggested that one object (usually the sensation of breathing) be kept in mind. One reason is that if you make an agreement with yourself to pay attention to just one thing, it's more obvious when you're distracted. So when you start thinking about your plans for the weekend, either you're willfully breaking your agreement with yourself, or you're distracted. It's easy to tell which.
Once you get the hang of it, you might move on to practices where thoughts are not banned. Sometimes they're even active supports. If you think meditation has to be boring, you may not have spent enough time yet watching what incredible acrobatics your mind is capable of.