You breathe, you are aware of breathing in and breathing out, even if you pay no attention. You eat and drink and you eliminate and you are aware of gustation, of the digestion of your food, of its progress through your body and of your digestion, the felicity or otherwise of your belly, liver and guts, you are aware of energy, of appetite, of solids, liquids and gasses etc., and again with or without attention. In the same way you are aware of the circulation of blood, of the state of your muscles and skeleton, of the work they do, need for rest, health or illness etc. Where your awareness is at best deficient and certainly more than a little misled is in the metabolism of thought and emotional feeling. This is a peculiar ignorance. Do you ingest certain ideas? They come at you from your engagement in the world, charged, more or less salient, and often they disappear just as quickly, only to emerge briefly, sea-changed, in dreams and intimations, before emerging some time later, excreted by your organs of thought and rattling around in your forebrain before being washed away by the next wave of preoccupation. This process is so mysterious that there is not any clear picture formed over the years of the structure and layout of these mental organs. The analogy breaks down, whatever it is that occupies your mind it is no kind of stuff.