You see, I, unlike you, have been made a prefect, which means that I, unlike you, have the power to hand out punishments.

One of the things Ford Prefect had always found hardest to understand about humans was their habit of continually stating and repeating the very very obvious.

Can't stay long, Mother," he said. "I'm up front, the prefects have got two compartments to themselves-

Harry, don't go picking a row with Malfoy, don't forget, he's a prefect now, he could make life difficult for you...