1. People in front of me that drive way slower than the speed limit, when there are no cars in front of them, during rush hour, AND esepcially when they drive some expensive sports car.
2. People asking redundant questions. These are questions where the their answers have already been mentioned earlier on. They are simply paraphrases of previous messages, sometimes to address attention from the audience.
3. General ignorance. When experts of a particular field also think they are experts in everything else. They have no respect for other occupations and think they are not as hard to obtain than their own occupation. Because of this, they are usually "do-it-alls" and refuse help from other people.
4. When people waste food. They order so much that anyone around them would know that they cannot finish the food.
5. People that only ask for freebies and are unwilling to have some substantial investment in time or money in whatever they want to pursue. I believe that output is usuallly proportional to input (hopefully).