Look again at the rocket as you saw it from large distance. You overlook (slices of) every moment the rocket has ever known or will know. And every moment (your moment) you see from all those rocket moments how they pass to the next rocket moment. Time goes by in the rocket, however it does so at a lower pace, and it goes by (for you) simultaneously at every moment of (a slice of) the rocket. You see simultaneously every moment of the rocket pass to the next moment of the rocket. The hands on every rocket clock have moved to the next rocket moment on that clock and for every clock this is a different moment. And every event is just as real as the others.
All this holds too for our own laboratory spacetime which was essentially not different from spacetime of the rocket (relativity principle).
Fig.5 Laboratory moment 3 passes to laboratory moment 4
The past and the future exist in the same amount as the present and every event that had ever happened or will happen, is still happening - or is already happening - in the same amount as the events of the now are happening.
This is what special relativity, isolated from other theories, is teaching us. You are there, on every moment of your live, and you live every moment of your live
But which or whose time is that
For ever means here: as observed from a coordinate system that moves by with a constant (nonzero) velocity with respect to us and then for all time, for every moment of this coordinate system. (However they see at every moment only one single representative slice from every moment of our universe). Our spacetime just is there, every moment of it passing to the next moment as an action-for-ever, existing for all moments of spacetime simultaneously - as observed from a coordinate system that moves with a constant velocity with respect to us.
There is no now. No past, no future. There is no highlighted NOW that is displacing itself along the fourth dimension, with a past of stilled colorless gray shapes behind and a future of vague shades, losing itself in the veils of the future, in the distance. There only are moments passing to their next moment, all evenly real, as an action that is. And the you-now is just as real as the you-earlier and the you-later, who accidentally happened to live elsewhere, there, somewhere along the fourth dimension. They are gone by or still have to come, but I think they really live, there then, or there later, as you now.