Yep. I was part of a "Free classroom" experiment by our school district when I was in 3rd grade where we could learn at our own pace and with our own focus on a subject.
I read all 52 books that had been published by that year in a month of school days.
I followed that with 6 weeks of playing chess and then finished the 3rd and 4th grade math books cover-to-cover in the next month. Then I ignored the English and spelling books for the rest of the year and never did them.
When I was done 3rd grade, they couldn't decide whether to send me straight to 5th grade or hold me back a year to finish the English and spelling bits. They finally chose not to make a decision...and sent me into 4th grade. :D