Rabbi Soloveitchik, in his humorous quip, was taking the midrash at face value, understanding Rabbi Akiva' comparison of Esther to Sarah as being merely a device to arouse his somnolent students. However, Rav Zadok ha-Kohein of Lublin, in his commentary Pri Tzadik to parshas Chayei Sarah, places the midrash in a wider context, and derives a very profound lesson from it. Why do people fall asleep during a Torah class? It could be that they are simply tired. However, if everyone in the class is falling asleep, it would seem that the reason for their sleeping has something to do with the shiur itself. Rav Akiva, according to Rav Zadok, was delivering a shiur on very lofty Torah concepts, and his listeners felt that the level of spirituality he was speaking of had no relevance to them, and, so, they fell asleep. R. Akiva, however, would not have spoken on such a high level if he thought that his listeners could not attain that level. Otherwise, why should he waste his time? In fact, the Tanna de-Bei Elyahu says that each person is obligated to ask himself, when will my actions reach the level of Avrohom, Yitzchok and Yaakov. Rav Zadok says Rabbi Akiva wanted to teach this lesson to his class, and he was saying that we must strive to attain the level of out matriarchs, as well.
Rabbi Akiva was demonstrating to his class that Esther, in a difficult situation, looked to her ancestor Sarah as a guide. We read in Megillas Esther that when she went in to see Achashveirosh to petition for her people against Haman's attempt to annihilate them, she clothed herself in her royal garments. The Talmud in Megillah says that this is a hint to the fact that she attained a certain level on the ladder leading to prophecy at this point, and received divine help in her efforts. Esther, Rabbi Akiva was saying, followed the lead of her ancestor Sarah. The midrash, cited by Rashi, tells us that all of Sarah's one hundred twenty-seven years were equal in goodness. She was able to use every situation in life as a means towards spiritual attainments. Rabbi Akiva was thus telling his class that all of them had the ability to bring meaning into every moment of their lives, just as Esther did, following in Sarah's footsteps. Therefore, the lofty spiritual levels that Rabbi Akiva was discussing in his lesson did, indeed, have relevance to each of his listeners, and they had no cause to fall asleep as he spoke.
It is interesting to note that Rabbi Akiva used the example of two women, Sarah and Esther, to teach his lesson to his class. Rav Aharon Soloveitchick, of blessed memory, often pointed out that it is a characteristic feminine trait to be able to find a deeper meaning in all that occurs in one's life. The Torah tells us, in our parsha, that God blessed Avrohom 'bakol' - with everything (Bereishis 24:1). A number of explanations are given by the rabbis for this expression, some of which are cited by the Ramban in his commentary. One of these opinions is that Avrohom had a daughter whose name was 'ba-kol.' The Ramban explains this to mean that the word 'ba-kol' refers to the eighth of God's midos, or traits. Although kabbalistic commentators on the Ramban say that he is referring to one of the sefiros, or divine emanations, Rav Aharon said he was referring to the eighth of God's thirteen attributes of mercy, the attribute of truth. This attribute, the Ramban is saying, is called 'bakol', and it is referred to by the rabbis as Avrohom's daughter because it is a feminine trait. Women, said Rav Aharon, are able to find truth and meaning in everything that happens in life, even in seemingly trivial things. The Torah is telling us that Avrohom was blessed with this trait, as well. We can perhaps speculate that he learned this trait from Sarah. It was therefore Sarah who Rabbi Akiva used as an example for his class, as well, urging them to strive for spiritual growth and attainment in every situation that confronts them throughout life, just as Sarah did.