Being index-indexed would decrease the size of a number you could count on your hands while maintaining a logical bit ordering by 768 (1024 - 256), so we should

Being index-indexed would decrease the size of a number you could count on your hands while maintaining a logical bit ordering by 768 (1024 - 256), so we should all be thumb-indexed. The proper comparison with endianness would be thumb- or pinky-indexed, but physiological limitations make pinky-indexing pretty useless (try counting to 2 in binary, starting with your pinky), so we should, again, be thumb-indexed.