An interesting feature of human thinking is known as 'reifying': making real. Imagining that because we have a word for something, then there must exist a 'thing' that corresponds to the word. But then, what about 'bravery' and 'cowardice'? Or 'tunnel'? In fact, what about 'hole'?
Many scientic concepts refer to things that are not real in the everyday sense in that they correspond to objects. For example, 'gravity' is accepted universally as an explanation for planetary motion, but what do we actually expect to see if we came across it? It is actually (as discovered by Einstein) just the tendency for objects not to move in straight lines, which we then reify as 'curved space'. For that matter, does 'space' itself exist, or is it just a privative? Similarly, many other concepts such as dark and cold are reified (some people may say to wear more clothes when it's cold to 'keep the cold out')
'Debt' and 'overdraft' are familiar concepts in our lives, but in fact they are just privatives. Today's derivatives market buys and sells debts and promises as though they actually exist, and these are reified as words and numbers on pieces of paper, or data in a computer. In fact, the more you consider, the more you'll notice that most of the world that we human beings interact with doesn't even exist at all. What exactly is the stock market? Or what does money actually represent for that matter?
Another interesting concept that is reified is Death. Often portrayed as a hooded skeleton carrying a scythe, it is actually just a privative for the absence of life. However, our fears of dying have lead to other reifications such as the soul or spirit of a body that must leave the body when it turns from a live body to a dead one. When a process stops, it's simply no longer 'there'. It doesn't continue on in another essence or form.