It struck me that eternity is not the stretch from the beginning to the end of all time - it is that plain where there IS no time. Only the physical plain requires time. We can only experience the physical through the lenses of time and space. In the eternal plain there is no time or space. The physical plain cannot be eternal because it relies on time. And the eternal spiritual plain cannot have time or space because of its eternal nature.
And now, a pretty picture of a Peony in our garden - because that last paragraph was complex and this is simple (although complex in its own way):
Just one of the things that goes through my mind on a Friday afternoon while I'm making potato salad.