We thought our son was reading when he was 3. He would "read" Dr Suess books letter perfect (even if we had only read the book together once). We started pointing out individual words, which he couldn't read, so we realized he was memorizing the book. He was, however, really reading middle of 2nd grade (400+ lexile), at least (teacher stopped testing at this point) when he started Kindergarten. He got him moved to fulltime gifted program, but I wish we had accelerated at that time also. He spent 5 years bored in school before he was finally accelerated.