I do something very similar, but with power-2 numbers (and have done since my childhood, long before I knew what power-2 numbers were). There's something very

I do something very similar, but with power-2 numbers (and have done since my childhood, long before I knew what power-2 numbers were). There's something very rhythmic about counting beats that line up with powers of 2 and I'm able to count things extremely quickly and precisely without even thinking about the numbers I'm counting. When I want to remember how much I've counted, I simply think back at where I am in the rhythm and come up with the results in a strange vibes-ey way I'm not really able to describe (for example, I'll just intuitively 'know' the difference between having counted 32 beats and 64 beats, and then I can use that knowledge to hone in on the precise number I'm at using a sort of mental binary search). I'm sure someone with more knowledge of musical theory or neurology could provide a better explanation, but it feels like I'm somehow taking advantage of whatever part of the brain keeps track of beats and rhythms in music, then using it to count. Edit: I just tried this technique while listening to music and, as expected, I completely lost the ability to count in this way. Almost immediately I lost track, before I even hit 16.