I can tell when I'm going to fall asleep. I can't take naps. I get plenty of sleep. Young people need less sleep. Being sleepy makes you misperceive things.
Coffee overcomes the effects of drowsiness while driving.
Drinks containing caffeine, such as coffee or cola, can help you feel more alert, but the effects last only for a short time. I can tell when I'm going to fall asleep. If you're like most people, you believe you can control your sleep. In a test, nearly four-fifths of people said they could predict when they were about to fall asleep. They were wrong.