One of my twins started reading at 2. The other didn't even really sound out words until he was 5, and in the beginning it was extremely difficult for him. Once he started reading, though, he progressed very,very quickly. But until he was "ready" it was almost impossible for him. He would not have been able to learn to read at age 4, even if we had tried.
In fact, we started trying to teach him to read around age 5, because he really wanted to learn and could sound out a few words, but soon stopped as it was so frustrating for him. At almost 5.5, the month before K started, he started working his way through the BOB books by himself. We would hear him reading them aloud, sounding out words in his room after we put him to bed. (He preferred to read alone at that stage.) Once he started K, he quickly moved through the reading levels until he hit the "ceiling" level for K in that school in January (which was end of first grade reading level). At home, he was reading non-fiction books that were at a much higher level by then.
It definitely just "clicked" for him once he was ready.
