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.
Douglas AdamsDirk turned on the car wipers, which grumbled because they didn't have quite enough rain to wipe away, so he turned them off again. Rain quickly speckled the windscreen. He turned on the wipers again, but they still refused to feel that the exercise was worthwhile, and scraped and squeaked in protest.
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