I was always skipping behind in English class, reading the literature stuff at the front of the book instead of enjoyed diagramming sentences and adjectival clauses as I should have been. From about age 8 onward I read anything I found mildly interesting, from cereal boxes to "Brave New World." When I didn't understand something I'd figure it out for myself. I probably knew what a Fallopian tube was before half of my classmates knew they had one.
Books I devoured at the rate of one every four or so hours if they were at my reading level or better, slightly beyond.