I didn't get a chance to read all the responses, but to answer your question: YES! We had a very similar experience. We noticed that DS5 could read at 18 months when he corrected his sunday school teacher when she had said the wrong word reading something on the wall. He had been reading some before that, but we assumed he just knew the stories of things since he had always loved books and we read so much to him. But it turned out he could actually read quite well at 18 months and continued to progress in reading. He is now 5, not sure what reading level but he can read anything. Maybe somewhere in the 6th/7th grade level? But his real interest is Math. He LOVES math. He is already doing algebra and probably averages around 6th grade level for math...but not quite sure. We did have him tested before school started and he is a PG child, which did not really surprise us based on all the early stuff he did. He ended up skipping K and is in first grade with LOTS of differentiation.