@Ergot: LOL.
The only test I had to take was for my permit. IIRC it was a 30 question test; I missed one, and IIRC you can miss six.
I did behind-the-wheel with my school, and with that paper from my driver's ed teacher, I didn't have to take a driving or written test at the MVD.
When I turned 21, I got a new license and did not require a test.
The reason I got a new license at 21 is Arizona's license design. Below 21, your license is long vertically, has the words "UNDER 21 UNTIL" in big red letters, and is Class G (actually I think it's only Class G until you're 18, but since I had the old style horizontal one I kept the class G until I turned 21). When I turned 21, I got the long-horizontally license that no longer says "UNDER 21 UNTIL" ;-)
Same situation for me, it was nice wasn't it.