I'm my own worst enemy:
I guess that is true of many people. It seems that I'm really good at shooting myself in the foot. I would like to break this particular bad habit. I guess that forgiving oneself is a start, but it would be nice to find a better way to do this. I have tried and failed many times.
I tend to under estimate the amount of things or supplies needed to complete a project (time, paint, bags of yard products, etc.). This is because money is tight, no sense in spending more than is needed to get the job accomplished. So this is one source of frustration.
Forgetting to cross T's and dot I's on government docs is another. I have really had enough of this system...