When people with narcolepsy are tired and sleepy, they may carry out actions without thinking about them and often with no recollection of them afterwards. This is called automatic behaviour. For example, a student in school may appear to be writing diligently, but what they have written turns out to be entirely inappropriate. They may also jump from topic to topic while speaking, or suddenly stop talking in the middle of a discussion. Such automatic behavious can be dangerous if it takes place when the person is carrying out a hazardous activity such as driving.