['Hi, I made a mistake at work last week', 'Oh no!  Was it a big one or not that big of a deal?', "It was a big deal to me, but I don't think anyone noticed."]
Oh good.  Well, at least its a big deal to you because that means you're taking things seriously and concerned about your work.
I had a problem at work last week. I solved the problem by breaking a couple rules.