The memory is the process of the mind. There are three major steps: 1) thoughts registers, 2) records of the thoughts are kept, and 3) records are either filed permanently away available to the sub-conscience or retrieved for use.
Much of the process occurs when a idea is registered. Then is the event that it's inputted, processed and combined with other inputs.
As an example, one day I considered the willingness of Abraham to sacrifice his son to God. I received the information externally and in this case from the Holy Bible. I processed the information and stored it away somewhere in my mind where things are stored. It was a great story!
Before then I had studied many times the crucifixion of Jesus. That too was stored in my mind. One day I had an epiphany: the sacrifice of Isaac was symbolic of and a picture of the sacrifice of Jesus. I had combined two memories in my mind! I have a record of each now and also a connection between those two thoughts. When I retrieve one idea now I get both because my mind has intricately linked the two by combing two thoughts into one grouping.
Without use, these thoughts are filed away. I can retrieve them when I need to providing that my mind is healthy and they have been used recently. If those memories have not been retrieved for a long time my long time memories become buried in the mind's dust with the sands of time. Only my sub-conscience can retrieve them, as hard as I try I can't get to them, but then maybe later the sub-conscience dusts them off and retrieves them for me; albeit I may prefer that they stay filed away.
My short term memory is great. It goes back about a day or two for me. Unless I really care about something, I dump most memories in the garbage bin of the sub-conscience. That's where I also try to dump unpleasant memories, but alas, the sub-conscience keeps dusting them off!
I'm good at forgetting sin. If I pleasure in the forbidden, I conveniently file them away in long term memory, but hope that they will be forgotten. I have placed many sins in that dust bin. Few will I ever recall. However, I do realize that I've filed away many sins. Some I have repented of, but others I have enjoyed and hidden the files in my memory under the heading of GBTF (guilty but trying to forget). If I forget that I did that sin before, then it's convenient to do it again because I can just file it away again!
I was born-again when I was a teenager. At that time all my past sins were forgiven (Romans 3:25). Jesus blood cleansed them from my soul, but many are still filed away as memories. If I look back as Lot's wife did, I can feel guilty for those forgiven (and that's Satan the memory retriever) or I can relive the sins in my mind (again, Satan at work). Those belong to Satan and his team because God has already forgotten them (Hebrews 8:12).
You see, God has the ability to forget, but we don't. However, part of the peace in being a Christian is realizing that God has the capacity to forget sins, and if we live for him, we can leave them filed away as well! There is no essential use for remembering past sins. It is good to remember that we have sinned and come short of the glory of God (Romans 3:23), but the specific past sins can and should be forgotten. They are useful for Satan, but detrimental for us!
Paul advised that we should forget what is behind and strain on what is ahead (Philippians 3:13-14) and to keep our eye on the prize (salvation). This means to "not look back" as Lot's wife was told not to do. Looking back killed her and it can make us die a second time!
This is in contrast to psychotherapy which would direct a person in counseling to have a break-through with the past as a means of closure. Closure for the Christian is by the propitiation of Jesus' blood. If we continue to feel guilty for sins already covered, then we neglect repentance of those current sins we have every day. We are sub-consciously being directed by Satan.
In the Holy Bible "remember" is used 210 times, mostly in reference to God. Being omniscient (all-knowing) he never forgets anything unless it's covered by the blood of Jesus. Being omnipotent (all-powerful) God can forget at will! Whereas, our sub-conscience can always drag memories out into the light of the mind, God's Light dims those memories from his and exposes them as useless.
Right now I have recent memories of sins that I've done. Jesus' death covered those sin, but for the efficacy of the blood, I need to repent of present sins. God remembers those until I repent and until I do that, they can still be recalled to haunt me. This recollection of unpardoned sin is of the Holy Ghost. Jesus is not pleased with my lack of right-living and his desire is that my new person have the traits of righteousness. His desire is that I (and you) be set apart from the world and become a new creature. This new person still sins, but has sorrow and repents of it. When repentance happens God wipes the slate clean and we resume our new personalities.
With repentance comes forgetfulness. Those sins are behind so why bring them up when even God has forgotten them? Lot's wife should have forgot what was behind and look toward the prize ahead. What was the prize? Immediately she would have went to paradise on earth (Israel), but in the end to paradise in the Kingdom of God. By looking back Satan grabbed her spiritual hand, took it and she died right there on the spot, both the first and second death. She remembered the pleasures of sin, rather than the hope of salvation!
If Lot's wife had looked ahead rather than back, she would be saved and even recognized that it was by God's grace even though she was a sinner. However, she had no need to look back because as she was safely out of the city, she had the hope of salvation!.
For us born again, we too have the hope of salvation. All we need to do is keep our eyes on the prize and not looked back! Of those saved by the parting of the water in Moses time, many looked back at the comfort and pleasure of Egypt and died right there on the spot.
God is gracious. We can accept his grace and look ahead, or not trust him for salvation, and look back. Our eternal destiny is always a choice. My desire is to look forward to the prize. God forgets and I need to as well!