xkcd #3232: Countdown Standard
Title text:
Anyone who is caught counting 'three ... two ... one ... zero ... GO!' will be punished with a lifetime of eating only ISO standard food samples.
Transcript:
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Source: https://xkcd.com/3232/
You ignite the rocket before liftoff though?
Right, but if you don't say it, they won't have ignited.
It's similar to the reason rain dances work. They don't stop dancing until it rains.