It's not the stupid that bothers me as much as it is the ignorance, and not even so much the ignorance, but the perverse pride that the ignorant take in their own ignorance. People proudly wear their lack of knowledge like it's some kind of achievement badge they earned for drinking the most turpentine without quite dying.
I understand that there are some subjects that will never interest some people. If somebody tells me that they have no interest in learning about a certain topic because it does not interest them, I will take them at their word and try to refrain from being judgemental, even if it is a topic in which I have a great deal of interest. I may consider them a dullard at that point, but I will cede their right to be one. There are matters out there that hold no interest for me, and I am sure that there are people who consider me a dullard for having no interest in learning about their passions.
On the other hand, I hold people in much lower esteem when they preface their statement ignorance with, "I am proud to say that I know nothing about X..."
That declaration can be implied, by expressing ignorance in something that could be figured out with a modicum of critical thinking.
A special lad posted a picture of a carton of Ice Milk today and said, "wtf is ice milk?"
I snarked at him that ice milk is exactly what it says it is.
There was a picture of the product on the carton. His picture included the ingredients list. A moment of critical thinking might have led one to conclude that ice milk is the same thing as ice cream, but with less fat content. Or, you know, just made with milk.
It's not rocket surgery. It just required thinking from somebody with an aversion to thinking.