I don’t spend much effort thinking about this sort of issue, since I’m much more interested in the experimental aspects of measuring time than the philosophical aspects of it, but I’ve run across some folks who think this problem of “Now” is so perplexing they can’t get past it. (again, because my interests lie elsewhere, this seems more of a dorm-room discussion, or possibly one involving a professor who looks like Donald Sutherland discussing whether atoms can be universes). My view of the utility of this is that while “It’s always now” may or may not be deep thinking, it doesn’t help GPS tell you where you are. (unless “You are here” is an acceptable answer)
[R]egardless of whether you use an external definition of time (some coordinate system) or an internal definition (such as the length of the curve), every single instant on that curve is just some point in space-time. Which one, then, is “now”?
Later on there’s also an interesting point about memory not needing consciousness.