Philisophical time

I can feel time,
I can feel it like water, draining away in my fingers,
Or sand moving through from the top half on an hourglass to the bottom.
I can feel myself in the centre of the hourglass, feel the fine white sand passing by.
And yet, the space in the middle of the glass cannot exist,
For it represents the present.
How can the present always be there,
For whenever the present is, it is instantly the past.
So surely, now cannot exist, because the world is always changing.
There is never a moment where the world is the same, because something’s always different.
So how can the future get to the past, if there’s nothing for it to pass through?
And even so, there is no such thing as the future, or the past,
Because, for something to exist, it has to be something, not anything.
And how can the past exist, if we cannot go back to it?
So there is really just now, ideas and memories.
But that makes no sense, because now can’t exist, because anything that exist instantly becomes memories.
So can just memories and ideas exist?
Is the whole world just a memory?
Then where do the memories come from? Ideas?
But the ideas can be anything, it doesn’t have a fixed form!
So is it possible there is something, in the now that doesn’t exist, takes in the ideas,
And gives them form? Makes them memories?
And surely, we are in the now that we cannot access, that doesn’t exist?
So is it us that defines the past?
Maybe that’s true. Maybe each individual person defines reality.
If so, we’re in a whole heap of trouble.