Or were all the old second counting systems wrong?
Many people have pointed out that if you start a timer on your phone and count out to 45 Mississippis, hippopotamus or number-one thousands it now ties out to a minute.
I have tried it a dozen times myself and after 45 counts I get anywhere between 54 to a minute and 4 seconds.
I specifically remember counting chunks of time as long as 15 minutes and not being off by a minute.
As you become older, your sense of time is much different. On a large scale, 1 month is 1/24 of a 2 year old’s age, while for somebody who’s 40, it’s 1/480 of their age. Time seems to run faster as you have been on the Earth for much longer, and I would guess that applies for small units of time too, like minutes and seconds. As a kid, you think that an hour is ages, but as you grow up an hour seems to go by much quicker, even though time still ticks as it always does on Earth.
You, being older now, count slower as time feels like it goes by relatively quicker. Counting “Mississippis”, “hippopotamus”, etc. are guesstimates at best and aren’t accurate measurements, being affected by how you believe time is paced. Obviously you could try to say it super quickly (when playing hide and seek as kids, me and my siblings used to do this) or ridiculously slowly, but you don’t as you have a general understanding of how long a second should be, and this idea of a second changes as you grow up!