In reality, there is only NOW. All our lives at any moment there was the present now.
Forget the clock for "now." Think of day and night, dark and light, constantly revolving as the world turns. It's so reliable over eons of time.
And for every person at all times there was only now.
And when we die it will be now. When we are gone people will live in their now.
I expect that in the existence after we physically die everything will be totally different.
People who have NDE (near--death experiences) have a slightly different tale to tell. It may be different for everyone.
The constantly changing (in one sense)
and never changing (in another sense). Now.
Some people may never think about now at all,
and others think about it all the time.
For me in recent years I think about it all the time. (maybe because I'm retired now and actually have time to think.)