It could be, I was really slow to learn to read (and I mean slow, I nearly ended up in remedial classes) until I got exceptionally lucky in having a teacher who realised my issue wasn't capability it was boredom and who was willing to give up her lunch time to introduce me to books that were engaging (I still remember the first 'proper' book I read, 'Goodnight Mister Tom' by Michelle Magorian - The critical point was when I wanted to know what happened next and began (laboriously) reading it at home so I could find out) - at 7 I had the reading ability of a slow 5 year old by 8 I was reading books typically read in school by 16 year olds.
Once I found books and authors I liked I became a voracious reader, from eight to adulthood it wasn't unusual for me to have 3-4 books on the go at once and to read 3-4 books in a week all the classic works of sci-fi, books on science, computers, geography, history, politics, biology I was a sponge, I'd read almost anything - I used to read while walking to and from school, I walked into surprisingly few lamp posts.
The more I read the less I vocalised the words in my head, I started with pointing at each word (as most kids do) and then I stopped doing that, then I started looking at the word shape rather than the word and not vocalising it at all, it wasn't anything conscious just a natural progression.
In a very profound sense that teacher and my mum altered the scope of my life for the next 30 years, the teacher by realising I just needed the time and the right material and my mum for scouring charity shops/2nd hand book shops to keep me fed with books as money was tight (bless her, she used to keep a list in her purse of all the authors I liked, what books they had written and which I'd read).