One of the greatest, if not the greatest motivator in life is the fact that everything is temporary. The keyboard you type on, the screen you view this on, the chair you sit on, everything is perishable.
That includes you. One day no one on Earth today will be alive. That is pending technological advancements of course.
So the argument is, why ever do anything if eventually it will perish? The counter to that would be, why not do anything, why not do something? The present is all you will ever have. Forgive your past and don't be fearful of your future. Without doing this, it's a never ending cycle, of comparing what matters versus what doesn't.
You are here. That is reason enough.