"... of course, nowadays the number one reason is tradition and familiarity given other popular languages, and I think even proponents of 0-based indexing would

"... of course, nowadays the number one reason is tradition and familiarity given other popular languages, and I think even proponents of 0-based indexing would agree, in spite of the fact that most of them wouldn’t even notice that they don’t call it a number zero reason." That's it, I'm switching to saying number 0 reason from now on. If you are talking about your number 1 reason, I will forever be wondering what your number 0 reason would be. I'll tell my wife tonight she is my number 0!