It's rude to plagiarize someone else's work.
Mike has to get his homework done but it's so boring and his brother James is already done.
Mike wants to get his homework done.
Mike does all the work himself and finishes his homework on his own.
Mike just copies James's work and calls it a day.
Mike gets an A for the assignment, the only one in his class to do so.
Turns out James didn't go very well on his homework and guessed at all the answers, so now Mike fails too.