For me, it may be that the toilet paper roll needs to have the open end away from the wall. I don’t want to reach under the roll to take a piece! That’s ludicrous!
That or my recent addiction to correcting people when they use “less” when they should use “fewer”
My response to the 10 fingers thing is that it’s easier to do certain calculations in your head. A lot of those calculations are larger than 10, anyway, so your fingers don’t help.
A third of 24 is 8. A third of 60 is 20. It becomes second nature after a while.
One place I used this a lot was 40k. In between rolls, I grouped my dice into sets of 4. When the next roll called for 12 dice, I quickly pick up 3 sets. If it’s 10, pick up two sets plus two dice from a third set. Made it really quick to count. At least for the base rolls, a lot of the stats in 40k tend to work in multiples of 4, so this worked out.