[kevindamm]

If you count with each finger as a binary digit you can count up to 15 on one hand!

255 if you use both hands!

More like 1023 if you also use thumbs but I prefer to use them as carry, overflow bits.

[soulofmischief]

I trained myself to do this by default a very long time ago and I can't imagine counting any other way.

It's so natural, useful and lends well to certain numerical tricks. We should explicitly be teaching binary to children earlier.