How do you number things in real life? If you have two options, do you number them "option 0" and "option 1" or "option 1" and "option 2"? If you create a presentation with numbered bullet points, do you start numbering them from 0 or 1?
1. This is my first point
2. This is my second point
Outside of programming, even most programmers use zero-based indexing only when they're making a programming joke.
Zero-based indices create odd effects even in programming, although we don't really notice them anymore.
Consider:
$array := ['a','b','c']
for($i:=0; $i<3; $i++) {
echo($array[$i])
}