Every Christmas day go to the bottom of your garden (or the garden where you are staying) find as quiet a place as you can manage and simply click your fingers, do nothing else.
Now try to remember to do the same thing next year on Christmas day, go to the bottom of the garden where you are and click your fingers and it will suddenly come in a rush towards you that the two clicks you suddenly remember that now appear seconds apart are actually divided by a whole year.
I have done this myself and it is an incredible way of defining how lightening fast the passage of time is.
The moral of the story does not need to be really taught as it becomes obvious that we should not waste our short time on this earth, we should spend our time as wisely as we decide.
Let me know if you have any other similar stories.