"Time is needed for any truly revolutionary teaching to be understood, and there are any number of intermediate stages.
In the history of Israel, it may be assumed that only during the time of the Second Temple did the people of Israel as a whole accept the Torah as an obligatory way of life.
From that time until recent generations, there has no longer been any serious division between the Jews and Torah.
They have been one consistent entity.
More than a thousand years elapsed, then, between the giving of the Torah and some sort of total receiving of the Torah.
Of course, it is not simply a matter of the spiritual and intellectual capacities of one generation or another.
So long as men are possessed of free will, the problem of receiving the Torah will be posed anew for every individual in every generation."
From an essay, "Eternal Torah" by Rabbi Adin Steinsaltz