Perhaps you mean it&#x27;s displacing not indexing?<p>Counting is indexing!<p>What is it that you do when you count items in a set? You put them into correspondence with the natural numbers, indicating each one as 1, 2, 3, ...  The last integer is the count.<p>Yes, it is related to the &quot;is the first floor ground, or the one above it&quot;; and it&#x27;s clear that some programming languages take their cue from stairs and elevators.<p>Nobody ever has to calculate &quot;what is the floor twice as high as this one?&quot; Moreover, people are unfazed by 13 missing.<p>(I haven&#x27;t seen a language that omits 13 from indexing, fortunately.)