Caught it. Mine too.
Understood (and no argument here), but I do believe it was criteria for hiring some of the big Top 40 jocks years ago. At the time, I'm sure some PD's (and DJ's too) were drooling over who could consistently do it better than others.
Many photographs of on-air studios show a Graylab darkroom timer, typically tied into the turntable control leads to start the timer.
Being able to walk up the intro of a song was somewhere between an art and a science.
Is it used much today?