WRITER: Is there any way that you can read a little faster or read more than one chapter at a time? Reading so little at one time and so far apart can lead to the tendency to forget what happened.
BETA READER: It is true I do not remember some details. You can look at that in 2 ways: 1) I suck as a beta reader and someone else might be a better beta reader for you. Or...
Maybe the thing I don't remember wasn't emphasized enough to stick in my brain so I could remember.
I am a writer, but also a reader. I started reading a book, put it down for 3 months, and picked it up again, and I still remembered what I needed to remember because the author made sure to emphasize the important things.
I like analogies, so here's one: reading is like driving a car. Some people drive faster than others. While they drive, they see the cool buildings and trees, mountains, aliens, whatever. The bigger the building, the better the driver can see it and it will leave a longer-lasting impression on their mind afterward. But if the building was right up against a tiny dog house, the driver isn't going to see the dog house. They're going to see the big building. So if you put an important plot point in the doghouse, switch it to the big building.
So I'm mostly a dork, but there you have it. I am only one reader and you should get opinions from others because they may feel differently. If I don't remember something, at least go back and see why maybe I don't remember. Was the mention of the thing only a single sentence, or an entire paragraph? I usually remember entire paragraphs of info, but single sentences measure up to the size of a doghouse, and I just don't see or remember dog houses.