I'm working on the Nova dress. I've been picking away at it for about 2 months now.
Despite it just being miles of stockinette, I've made at least two mistakes and one mistake that wasn't really, it was how the pattern was written but I didn't like it. Therefore the first three decreases are leaning the wrong way as I modified how I was knitting them but didn't bother to rip it back.
I did, however, rip back the first sleeve. Twice. First I tried to knit them two at a time, which I do for socks and is fine, but with striping, was a huge mess. Rip. Then I was about 4 stripes in, dropped a few stitches, couldn't handle it. Rip.