Game Of Thrones: 8 Outrageous Fan Theories About Daenerys Targaryen
4. R+L=D
We're all pretty used to the R+L=J theory by now, but what if - and admittedly it's a Wun Wun sized if - Rhaegar Targaryen and Lyanna Stark aren't Jon's parents, but instead are the parents of Daenerys Targaryen? It'd change a lot about how we think of these characters, and what we think we know of the final endgame of the series. Although we've heard plenty of Daenerys being born on Dragonstone during the storm - hence Daenerys Stormborn - there is a belief that this wasn't the case.
Instead, it goes that it was Daenerys who Lyanna gave birth to, with Jon being the son of Ashara Dayne and Brandon or Eddard Stark. This is supposed to fit better with the timeline, giving Ned more time to go to Storm's End before continuing on to the Tower of Joy, and also goes up with Rhaegar's obsession of creating the Prince That Was Promised and someone who would ride dragons.
This requires Jon being slightly older than Robb, and Dany being older than she thinks she is, as well as the whole lie of who her parents are as well as the misleading information about Jon's. Characters being older than believed isn't totally impossible, and it would be a big twist, even if there are a lot of dragon sized holes in this one.