It's easy to see how long food items last as most have a sell-by, date and with food and other items we own, after a time we start to see signs of wear and tear around the edges. Once this happens we either take the action to preserve them and get the most use out of them or we discard them as they have either run out life or have little use any more. It is clear with these things and we know that at some point we will need to acquire a newer option. We also have an idea in most cases when that 'D' date is coming unlike ourselves…