Just how dumb can one person be?

I'm still sick with a hacking cough.  It's not as frequent as it was and I think I've stopped startling the neighbors at all times of the night and day, but I'm sill not 100% well.

Anyway, that's not what I wanted to complain about today.  I'm old. I always have some kind of ailment somewhere to complain about.  Usually more than one.  Which reminds me I still have a pain in my back and down my leg from picking up that greeting card last month.  By the way, I finally sent it today to the high school grad for whom it was bought.  I was beginning to wonder if she'd get it before she graduated college.

Anyway, just how dumb can one person be?  I work with one of the dumbest people I've ever had the displeasure of working with.  He probably has at least an average IQ.  He just doesn't bother to use any of it. 

He complained yesterday that he couldn't understand or remember how to complete one of our forms that he has been using for a month.  Last night I stayed late at the office and created a "cheat sheet" for him that explained where you could find the information requested on each line of the form. 

I wasn't expecting a nice little thank you for my hard work in creating the "cheat sheet", but he sent me an email this morning that made me want to cry.  I wanted to cry because it's against the law to smack co-workers up side the back of the head for stupidity.  No matter how stupid they are.

He asked me about the email I sent with an update to the form and wanted to know which report he was supposed to update, X or Y.

1. In the first place, how could he think "cheat sheet" was synonymous with "update"?   Please, somebody, anybody explain that to me.
2. The reports he referred to were not X or Y, but A and Z.  Actually, X and Y aren't reports but a data system (X is the same thing as Y).
3. You can get reports from X/Y but they have nothing to do with the form in question.  
4. Reports A and Z can be used to complete the form, but not update it.  Nor can you use the form to update the reports.
5. Report A is obsolete and he was told to stop using it on June 23 and use report Z.  So actually you would only use report Z to complete the form.  

Anyway, that was just the morning stupidity.  He had more as the day wore on. 

Only two things are infinite, the universe and human stupidity, and I’m not sure about the former. ~ Albert Einstein