i don't like it when people leave me alone to do something (e.g. during exams when you have one last exam and the whole world thinks they're doing you a favour by leaving you alone) and leave you out of the loop.
or when people ask you to do something, and in the end, when they don't need you to do that anymore, they don't update you, they just give you a miss altogether.
it irritates me when there're chunks of missing information in the picture i'm seeing.