Why do People Commit Stupid Crimes?

We have all seen the videos of criminals that try to rob a store and then commit stupid crimes. My question is, why do people do that? Do they not think through how they are going to steal the money? If I were a smart person, I would know what I would do from beginning to end. On top of that, if I were to wear a mask to disguise myself, I would not put a paper bag on my head and cut off my vision. I would also rob a store with a real weapon, not a banana. All of these videos show how stupid people can be.