That irritating moment when someone is continuously clearing their throat in a silent room and you actually start counting the number of seconds in between their annoying throat clears and work out that they happen between every 3 and 6 seconds typically. That averages to every 4.5 seconds, which means they are clearing their throat about 13 times
per minute. And then that irritating moment following the previous irritating moment where you realise you have dyscalculia and someone's obxnoxiousness has resorted to you doing maths.