How do you think you could know that? It may be that with an infinite past we could exist at any point in the sequence of events. No matter what we always find ourselves in the now.
But if you exist at a point, then the amount of time prior could not have been infinite.
There’s additional time after the point of your existence, right? Well if there is additional time AFTER the point of your existence, then the amount of time BEFORE your existence could not have been infinite.
That’s the point - in order for it to be infinite, we could never reach this point. It would make the amount of time finite.
How do you think you could know that? It may be that with an infinite past we could exist at any point in the sequence of events. No matter what we always find ourselves in the now.
But if you exist at a point, then the amount of time prior could not have been infinite.
There’s additional time after the point of your existence, right? Well if there is additional time AFTER the point of your existence, then the amount of time BEFORE your existence could not have been infinite.
If there was no beginning how could it be considered finite? It would be an infinite series of events going backwards in time.