Now that it's been confirmed Jon Snow is the son of Rhaegar Targaryan and Lyanna Stark, fans have been rewatching the whole series looking for clues that could have foreshadowed the reveal.
Now, they've found a big one, from all the way back in season three.
It happens in a small, sweet scene between Davos and Shireen. The onion knight confesses to the girl that he doesn't know how to read. She tries to teach him, and the first word they read together is "Aegon." Davos was still serving Stannis Baratheon at the time, but this could be the first hint that Davos' next master would be named Aegon.
Notice how she also mentions that "Aeg" is pronounced like "egg." If you've read the books, this isn't the fist time that comparison was brought up. In the fifth book, Jon Snow recalls a story told to him by Maester Aemon. "It takes a man to rule. An Aegon, not an egg." The comparison also calls Daenerys' dragon eggs to mind. Perhaps the show was trying to hint at Jon and Dany's eventual partnership.
Shireen's reading lessons turned out to be awfully important to finding out Jon Snow's true parentage. The girl also taught Gilly to read, allowing her to stumble on the fact that Rhaegar had an annulment, and a secret marriage.
As fun as these Easter Eggs are, it's even cooler to find out that Shireen was even more important to the story than we ever gave her credit.