can just as well be asserted that the saying " live in the present is merely a metaphor. I am writing this determenently, in order to understand time, and end up with a metaphore, no matter how you slice it.
The present moment is already gone as soon as it is lived. We always live predeterminately on a conscious level, and in the proximate future as the last flows into the future.
This can be imagined or illustrated. by set theory as well.
The perfect essence of the imperfect reflection must end sadly, paradoxically, because perfect presence implies slicing the gap between the relative and the absolute set, up to a scintilla of a slice: where a scintilla is immeasurable.
Time expanded into the very tiniest segments end with uncertainty which is the quanta of temporality.
In that sense the flow of time covers that minute gap between conscious and unconscious flow.
There really is only relative time and the relation must be a measure of one signified epoch to another.
Signification depends on signs, and since the present has no sign , it is not significant enough to take measure of.
( look around you and see if you can re-cognise you that which was not there a moment ago?)
It is merely a metaphore, here and now, as well as the next nano second.
Imagination is , on the other hand, capable of recreating a time such as one can imagine of suspended animation. But then again, that implies Other minds, and verification of shared imminance takes more than telepathy, recognition .
That those kinds of states are absolutely certain to have arisen, is within the boundaries of certainty as well.