Mr Happy
if I run backwards in only even numbers I pass through zero at a value not dissimilar from 0. If I try with odd numbers I seem to skip over 0. In my book a series like "even" or "odd" has meaning otherwise I would fall over as I walk (you've seen me at festivals, eh?) and I think your argument would fall into a big hole at zero. Unless of course it didn't exist - which makes us both right at the same time. Now If I owewd you 10 poinds and we dispensed with the digits that don't exist I would save £9. How would you like the cash? in pennies - dispensing with the non exists I make it 1p. Afurther 99p saved. My lucky day.
Go figure.