Events that have occured at least once, have a possibility of taking place once more in the future. It sounds logical. But is it? What does it mean “has happened once”? Based on whose experience? Does it matter if we know it has happened or not? Does it matter whether this event has taken place in the past or the future? It surely seems illogical to think of events that will happen, but the time-scale is one and unified. If you use a time machine (modern physics accepts the possibility of creating one – even though no-one has ever created one) and go to the past, then events that you know have took place, will not have “happened” for the people living there/then. And to make it even worse, if the Universe exists “for ever” as some claim, how can anything NOT have happened ever?