I just made sort of a serious error at work. My boss asked me to do something and I did it, following his instructions to a tee. He then got mad with me, because his brief to me was inaccurate and hence the work came out all wrong. I pointed this out, in terms a child could understand, and upon realising the errors he committed, he graciously pointed out that I still should have known better. I'm lucky to work with people like that.
What's the matter with me? People rely on me to give them what they need, not what they ask for. I've been doing this job too long to make a rookie mistake like that. The fact that I spent five hours doing eighteen versions of one letter, including being at the office on a Sunday at 7am, and that I'm going to have to do them all over again, really doesn't come into play.