Is there good reason to believe that this is what is really meant by "I am who I am" and isn't just Christians reading philosophical ideas back into the OT? (I

Is there good reason to believe that this is what is really meant by "I am who I am" and isn't just Christians reading philosophical ideas back into the OT? (I ask this actually because I remember Ratzinger raising this possible objection in Introduction to Christianity (some of which I read long ago, though I don't have the text with me anymore), presumably to rebut it, though I don't remember his rebuttal.)