Which group adhears to the idea of heavenly amnesia? Ok related to this questions Will people in hell be able to remember people in heaven? , either some individuals or indeed whole groups believe in some form of (for lack of a better term) "heavenly amnesia" where you have no memory of your life once you get into Heaven. Where did this idea come from? Is there any group that officially holds this position to be true, or is it some folklore. (I only say this because the first time I heard about it was from the old folk tale where death is trapped in a bag) 
As was expressed in the other question scripture refutes this, but there are groups out their that believe things other than the scripture and use them to explain away plenty of other things. 
How widespread is this idea?
The Bible says that there is no sadness in Heaven, e.g. Revelation 21:4 "And God will wipe away every tear from their eyes; there shall be no more death, nor sorrow, nor crying. There shall be no more pain, for the former things have passed away.” 

So a common argument goes: There is no sadness in Heaven. If I knew that this person I loved was in Hell that would certainly make me very sad. Therefore it must be that I won't remember them.

To the best of my knowledge there is no more specific Scriptural basis for this theory. And thus I think it's weak. I can easily think of other alternatives.

To take a personal example: My wife left me years ago. In my opinion, she made a real mess of her life, can't hold a job, gone through a series of men, etc. The kids and I feel sorry for her, but for the most part we basically say, "She did this to herself. This is the life she wanted." Okay, some of that is resentment for personal hurts. But if I was a perfect human being, would I being crying for her every day and being miserable because of what she's done to herself? Or at some point is it reasonable and normal to say, "I tried to help you, but you made your choices." This appears to be God's attitude toward sinners. Of course he went way further than I have ever gone for anybody, allowing himself to be tortured to death to save anyone who would accept his offer. But those that don't, eventually he says, "So be it." I think it is plausible that in Heaven we will have a perfect understanding of justice. People are in Hell because of choices they made.

That said, there is one scenario that does really disturb me. My mother once said, what happens if she gets to Heaven, she stands before the judgment seat of Christ and he says yes, you are among the saved. Then the next person comes up and Christ says, No, you are condemned. And then this person turns to her and says, You knew how to be saved, but you never told me?