Why does it take so long to "recall events"? What's really happening during this time?

I recently initialized my PS4, wiping its internal memory completely. Today, I reinstalled inFAMOUS First Light and downloaded my latest save game from the Playstation Online Storage. Upon first loading the game, I was presented with this screen:

What is my PS4 doing when it says it's "recalling events"? And why does it say it will take almost two hours to do so? That's longer than it took to download the entire game!