Speaking as the author of the OP, I can assure you that there was no such presupposition. My goal in this thread was not to validate or invalidate Calvinism based upon the number of people who believe it, but instead to show the apparent inconsistency with holding to a dogma where God effectually draws people to believe the tenets of the gospel while not also effectually drawing them to the tenets of how they were saved.
Some Calvinists believe God does draw all true believers to a Calvinistic understanding of faith and some for this very reason dismiss non-Calvinists as unbelieving heretics.
Other Calvinists believe God draws men to salvation and then leaves them free to choose and discern all other matters of faith. (I have questions for those in this camp and thus am searching for them)
So, instead of presuming upon the OP, why not just answer the darn question?
Frankly, the OP question is stupid. But since you have defined your presupposition, which forces me to accept that as your meaning (I have no problem doing so) I will address that. A question is only as good as its presupposition.
It does not follow that a person who is truly saved that God is somehow obligated to reveal all knowledge to them. It may please the Lord to leave some persons ignorant of certain truths while enlightening others.
I doubt your own self when you were but a babe in Christ understood the doctrine of the Trinity which we both affirm, or the intricasies of the hypostatic union as we have come to call it today. Yet God was well-pleased to save both you and me and leave us for a time not fully comprehending those doctrines.
And which of us is ascribing glory to themselves and not to God alone and His grace for their salvation?
God is not necessarily interested in making engineers out of all His children. Many of us are quite happy with enjoying the light without understanding how it works.
When discussing the doctrines of election and predestination we must tread very, very lightly, reverently, cautiously, and Scripturally. Because to do so is to gaze into the secret counsel of the Almighty.
When the Scripture tells me He chose me before the world began...I believe Him. And I think you do too. When Jesus prays, not for the world, but for those who will believe, I believe He is doing exactly that...interceding for believers.
As for the "some calvinists" you mention, I have no idea who these people are or what they believe. My advice in your studies is to stick with historic Calvinism. Look to the Calvinist creeds, and the writings of those in the past and today who are well-respected and have earned a good testimony among many...espeically of those who have fallen asleep in Christ and we see they have finished well...men like Spurgeon, Whitfield, Gill, and others.