Yeah, something clicked while I was reading an old encyclopedia sometime around age 7; I remember it quite vividly. My brain started being able to process chunks of text at a time instead of single words, so I could sort of focus on the middle of a short sentence or phrase and read the whole thing at once. I went from reading at about one-quarter conversation speed, to about ten times conversation speed, over the course of a few minutes. I still don't quite understand what the process was that enabled the change; I just sort of experienced it happening.

One trade-off is that I don't have full conscious recall of each word when I read things that quickly - but I do tend to be able to pull up a reasonable paraphrasing of the information later if I need to.