There's something that happens to me with an alarming frequency, something that I almost never (or don't remember) see being referenced (and thus I don't know the proper name). I'm talking about that effect when I'm reading a text (any kind of text, textbook, blog, forum text) and suddenly I discover that two minutes passed and I advanced six lines in the text, but I just have no idea of what I read. It's like a time blackhole, and now I have to re-read it.

Sometimes it also happens in a less alarming way, but still bad: for instance, when I'm reading something that is deliberately teaching me an important piece of knowledge (as in, I already know whathever is in this text IS important) I happen to go through it without questioning anything, just "accepting" it and a few moments later it suddenly comes down on me when I'm ahead: "Wait... what, did he just say 2 pages ago that thermal radiation does NOT need matter to propagate?" and I have again to go back and check that I was not crazy.

While I don't know the name of this effect, I have asked some acquantainces of mine about that, while some agreed that they have it others didn't. I would like very much to eliminate this flaw, anybody knows what I could do to train myself not to do it or at least the correct name so I can research more about it?