I'm the same way, but I figured out a little trick that has worked splendidly. I read out loud. There's something about hearing what you're reading as well as speaking it that helps it imprint in your mind. This is how those language courses like Rosetta Stone work. it's more immersive, and you can immediately catch yourself when the mind begins to wander. it's like a form of meditation.
I can sometimes have over a dozen books laying on my nightstands bookmarked. It's just like watching programs on television. I pick up one and read a chapter or two, then set it down and pick up another one and read a chapter or two, etc. You'd be surprised how much time you can spend reading when you're reading a dozen different books at a time. The cool thing is that there's so much going on in all of them, and you're reading all of them almost at the same time so you've got all these ideas going through your mind simultaneously. I love it when I'm reading about something, and one or more of the other books I'm reading is talking about something related or even the same thing. It's bizarre sometimes.
Sometimes I'll be reading something, and there's something so amazing that I have to check their bibliography to find out where they got this information. Then I'll go to the library to get a copy of that book, and while I'm there, I'll literally see a book that captures my attention for no other reason other than it might be sticking out, or the title, etc. I'll get that one as well, and start reading it only to find out that it's related as well, or also one of the books in the bibliography of the other book I just read or picked out at the library.
I've discovered that using highlighter pens, especially yellow; is useless after a decade or more. They just fade away so now I underline everything as well. I also use a straight edge, and have found that for some reason it makes rereading what I underlined more pleasant because i don't have to struggle to read between a bunch of squiggly lines anymore which in itself discouraged me from going back to reread underlined materials.
I also dog ear, or paperclip what I've underlined which some people frown upon, especially the hard line bibliophiles, but then they frown on underlining as well. I always liked having used textbooks when I was in school because of the notes underlined material etc. I like to know that others read it before me for some reason. I guess I like to know that what I'm reading is really worth reading to someone other than just me.