It's mathematicians. Most notably, both the ordinal numbers and the cardinal numbers start at 0. 0 the cardinal number is the number of elements of the empty s

It's mathematicians. Most notably, both the ordinal numbers and the cardinal numbers start at 0. 0 the cardinal number is the number of elements of the empty set, the smallest possible set. 0 the (von Neumann) ordinal number is defined as the empty set {}; 1 is the set composed of the empty set, {{}}; 2 is the set composed of 0 and 1: {{}, {{}}} and so on. Thinking of 1 as the zeroth number is only useful because of a quirk of human language and history.