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:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3232/


The real problem in my opinion is people count too slowly and irregularly for a precise sync up. Better to learn from the world of music and count off
You can count me in like that but I insist a full measure of Mars, Bringer of War.
This is why you have a practice count! “On three, everybody… one, two, three!”
“Okay, got that? Here we go: one, two… three!”