A 25-year-old man presents to the outpatient clinic complaining of feeling sleepy all the time, even during the daytime. The symptoms have persisted for years and are now brought to medical attention after falling asleep at work on multiple occasions. He is concerned that he might lose his job. He has no past medical history and is not taking any sedative medications. On physical examination, he is slender and the heart and lung exams are normal. Neurologic assessment reveals normal orientation, memory, concentration, and no focal deficits. Which of the following symptoms might he also complain about?