Oh yeah! I was on a roll with a for-loop using the pins as 2-21 after I soldered it. I put a bunch of leds in a row. I first started with the d2-d13. Then I realized you just state the analogs as 14 onwards for analog pins.
I got that much worked out. Then I got really frustrated with 20 and 21. I thought I must have busted up on the soldering! But when I realized neither 20-21 was working, I kind of sussed it. I was going wild trying to work out if the jumper cables were busted or something.
I got really mad!