The Talmud Yerushalmi Peah 2:4 - (daf 13a) states:
ריב"ל אמר... אפי' מה שתלמיד ותיק עתיד להורות לפני רבו כבר נאמר למשה בסיני מה טעם (קוהלת א) יש דבר שיאמר אדם ראה זה חדש הוא וגו' משיבו חבירו ואומר לו כבר היה לעולמים
R, Yehoshua Ben Levi says... Even that which a senior student will lecture in front of his master, was already said to Moshe at Sinai. What is the reason (source) of this? [From the passuk: (Koheles 1:10) Sometimes there is a phenomenon of which one might say say, “Look, this one is new!”— And his friend will respond and say to him "it occurred long since, in ages that went by before":
The Yerushalmi says that everything taught by students in front of their masters was already said to Moshe at Sinai.
In Menachos 29b we see Moshe Rabbeinu join R' Akiva's shiur and:
אמר לפניו רבש"ע הראהו לי אמר לו חזור לאחורך הלך וישב בסוף שמונה שורות ולא היה יודע מה הן אומרים
Moses said before [God]: Master of the Universe, show him to me. [God] said to him: Return behind you. Moses went and sat at the end of the eighth row [in Rabbi Akiva’s study hall] and did not understand what they were saying.
If Moshe Rabbeinu received all Torah that would ever be learnt at Har Sinai (Yerushalmi Peah), why didn't he understand R' Akiva's shiur? He had already learned/ received that Torah!