Imagine that you are “travelling” along a string of sausages representing time. Within each sausage you have full experiences and near-term memories of whatever you are doing. When you change state (such as getting on the plane coming back from vacation, go back to work) you twist up the sausage and create a new one. From the new sausage, the old one seems a very long way away, even inaccessible and your long-term subset of memories starts forming.
That’s my sausage theory of time.[NB at the time of writing (2007), it was a unique phrase – I claim copyright. No hits on Google]