In the Midrash, we learn that HaShem created the world initially out of Din, (judgement/might) and then joined it with Rahamim. (Mercy)
The Ramhal (Rav Mosheh Hayyim Luzzato) along with other mekubalim, (like R' Immanuel Hai Reiki in Mishnath Hasidim) explains that this Gevurah (Din) is the initial Tzimtzum that created the empty space into which the world was created. As they explain, the Tzimtzum is the root of the creation of the kli, the vessel.
It seems to me that the reason our Yirah must precede our learning, our Hochmah/wisdom, is because we need to create the vessel first that will contain our learning.
The Notzer Hesed explains that learning the secrets of the Torah, in the Zohar and the recorded writings of the Arizal, gives us proper Yirah. He says that even young children should be educated in these secrets so that they will have proper Yirah.
From this we can perhaps even understand that the learning that we do that is not l'shmah (for its own sake) still leads to learning l'shmah, because it creates the vessel for our future learning. How does it create the vessel? Through our learning, we see how much we don't know, we learn that there is so much still to learn, we get the smallest glimpse of just how great HaShem and His Torah are. This brings us to awe, which creates the vessel for our future learning.