The problem with the commemoration of all souls is that it is meaningless unless we accept that which is contrary to our common experience.
We live in and are totally immersed in a dimension of motion and time.
Time is simply the measure of motion.
When we die we enter into the timeless and motionless dimension of eternity.
There is no yesterday and no tomorrow. Just the eternal present.
This is of course beyond our imagination.
One of the effects of this reality is that our prayers and Masses, though uttered at given times on behalf of our departed loved ones have related limitations when it comes to Divine response and application.
In other words, years after a person dies, the prayers and Masses we offer for his/her soul are heard and applied within the context of their need and Godís mercy, without any consideration of time ...so that the unique prayer I say today might well have been actually heard and answered 20 years ago! Therefore to say it makes no sense not to pray for someone because they "must be in heaven by now" ...is to miss the point entirely. Never stop praying for your beloved dead and rest assured that it is in no way contrary to reason for you to do so.