Exactly, often I find that I don't even necessarily need sleep when drowsiness sets in. Just getting out of the car, walking around and stretching or pulling over and closing my eyes for half an hour brings me back to wakefulness. This is after driving five or six hours, not being awake eighteen, though.
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A gentleman should always be able to break his fast in the manner of a gentleman where so ever he may find himself.--Good Omens