No one has the parents they think they have

[Ser Charles of Rosehaven]

Could be, could be. It doesn't explain the awesomeness that is Oberyn Martell, though. Unless.... Darkstar is the product of a threesome! That is why Darkstar is "of the night". And it makes Oberyn even more amazing.

Sounds legit.

[Jm4n68]

Finally The thread has been created. I knew I was not the only one to notice.....these babies need mothers! Dudes just don't scoop up bastards-to-go, and why don't we see the Mothers more often? (They are mostly deadish, some maybe be Others/Wights)

Its because the few moms that survive child birth are being held. To keep the identities of everyone a perpetual mystery, to maintain stability in the realm....but how? These mothers keep themselves busy, gazing into the live's of their children, and their futures. Where could they be!?

Oldtown. You think your Maester is being helpful? One moment he is tending to the wife giving birth and BAM now thats his trueborn son and your wife is dead. Your Wife if dead. that was the one you were friends with too.

We need to send a young, virile lad like Podrik to the catacombs of the harems of Oldtown. That motherfucker has work to do....

[Viserys - The last dragon]

Aegon VI was clearly actually the child of Ned Stark and Elia Martell - why do you think Ned was so torn up about Aegon's death? Ned took her for a ride on his direwolf at Harrenhal, and 9 months later the usual thing happened, but Rhaegar was too oblivious to figure it out.

Daenerys is similarly the result of an encounter between Ned Stark and Rhaella Targaryen; he caught them fleeing King's Landing after the Trident. He let them go because he's a cool guy, but not before doing what the Ned does best.

Jon Snow? Ned and Lyanna. Rhaegar's kidnapping plot was supposed to be a cover for them to hook up (Rhaegar was down with the incest thing, being a rather inbred guy himself), but it went horribly awry.

Sam Tarly? Ned didn't like the look of Randyll when he was breaking the siege of Storm's End.

Robert Arryn? Ned got lost on his wedding and one red-headed lady looks much like another in the dark.

Did I miss anyone?

Finally! A theory which makes sense!