There are several rumors, and no one really knows which is accurate. There are two likely reasons:
1) As previously mentioned, Walt's speech.
2) If any of you are familiar with the film Sleeping Beauty, the 3 good fairies literally put the rest of the castle to sleep, "until Rose awakens." They even put the candles to sleep-so, of course, they put the clock to sleep as well. Just a cute refe
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