I get what you're saying, and I think I have a decent (enough) analogy to illustrate the difference.
The memory gaps you are talking about are sort of like lossy compression. The gist of what happened is there, even if you can't remember every detail. Blacking out is more like having a significant chunk deleted from the middle of the file.
Re:Only some people get blackout drunk
by pavel_lishin on Friday June 15, 2018 @12:04PM
(#17320792)
The "after awhile" part is the key, there. I also don't remember what I said to my home room teacher on January 19th, 1996 - but I remember largely everything I did yesterday, if not in a eidetic manner.
Can you really remember a all connecting history without any gaps?
I bet there are always some gaps in the middle, where there is just nothing.