I came across an interesting video on another YouTube channel a few minutes ago. The title is “Something Erases Your Memory While You Sleep” on the Riddle channel. I won’t post the link, but you can search for it at your leisure.
In a nutshell, the discussion is about the role of MCH (Melatonin Concentrating Hormone) during REM sleep. We know that REM sleep plays an important role in locking our experiences into long term memories. The surprise that is raised in the video above is that MCH appears to erase memory, not preserve it. Hopefully that is not too much of a spoiler for those who want to watch it for themselves.