What does this mean?
I am sure this would not have been possible had I remained a typical Anglophone North American.
I have never heard that before and I really find it strange.
I deduce that it means
I am sure this would not have been possible if I kept remaining Anglophone North American.
But I might be wrong in this.
Best Answer
Conditions and Their Consequents
A conditional statement has two separate clauses, each with its own subject and verb: the condition itself, and the consequent that occurs only should that condition be met. There are fancy Greek words for these two pieces (protasis and apodosis), but I’ll stick to condition and consequent here.
The important thing for you to understand is that the ordering of the conditional’s two clauses doesn’t matter, because it is always clear which is the condition. You can have condition followed by consequent, or you can have consequent followed by condition — which is what’s going on with your particular example.
Additionally, clauses are also potentially subject to auxiliary inversion:
Here follow several simple examples, saying which sort of production is operative in each in the parentheses following.
condition → consequent
consequent ← condition
Rewriting Your Sentence
As the linked-to questions show, your example sentence is one of the lattermost variety: it places the consequent before the condition, and it uses if-deletion and inversion in that condition. Rewriting your sentence through successive transformations shows you exactly what it means:
English has always supported bare conditionals like this, those without a conjunction. Back when it was more strongly inflected, this was always clear because that inversion also triggered a subjunctive inflection. Our last productive vestige of that is with the special form were.
Nowadays a bare conditional is most easily recognized by the obligatory inversion it demands.