Pictured below is a perfectly cromulent hat, right? It looks fine (other than that the needle was taken out already). It's nine cables, and now has the right number of stitches picked up:
Well, it's not. I miss-crossed every single cable, and didn't realize it until I started reading the directions for the decreases. I was too busy trying to knit it on the subway and at lunch to bother really reading the chart. Oh, don't get me wrong, I looked at it. I looked at it long enough to memorize what rows to cross on and to see that it was a 5 x 5 braided cable. But for some reason, I completely mis-read the cable symbols. For this I have no excuse, as they're not unclear (and there's a symbol key right next to the chart in case they are). I remember looking at it and thinking I comprehended it, though, so I never took a second good look.
'What else is new?', is all I can say now. I make this error more times than I care to admit. I do my quick-read and think I got it, it's easy, I can't possible screw it up...just to see later that I was wrong, and it was in front of me all along. It's not always that I don't bother reading ahead and assume (which I sometimes do too, but that's another issue), it's more like my brain's putting what I was seeing together differently than what was actually there. Or maybe I'm not looking with enough attention, and my brain is filling in the gaps so I think I read it.
It's a funny thing, actually, the way the brain does this. Most people don't notice, especially when, you know, it works as intended (that is, we fill in the gaps from what we see and are right). Humans are really good at seeing patterns and connecting the dots, so good, we'll see them when they aren't there. And this is only one way we can be tricked by our brain (if you're interested about this topic, a good book is Don't Believe Everything You Think by Thomas E. Kida).
However, knowing about it doesn't mean one stops doing it, especially when one is being sloppy and self-confident. I'm not self-confident about many things, but at this point, I consider myself a decent knitter. I don't know everything by far, but the things I know I can do pretty well. But this sometime leads me to skimming patterns in the interest of time or laziness, and thinking I know what's going on. Or thinking I know something and I really only have a hazy idea (or remembered wrong). Being a fast sight-reader doesn't help this matter; I can read fast, but if I'm being less than attentive I will think I just read it fast when I didn't really capture everything on the page (and again, the brain connects the dots). Which is how I get the wrong instructions stuck in my head, follow them, only to find out later that if I had just looked more carefully at the paper, I wouldn't be wasting the time in which I could be knitting my main project ripping out and restarting my travel one.