I could write a book on the rumors that sprouted from the lives of the Bear and the Boar. Here are some of the more common ones...

1. Beregard is mentally unstable, some terrible beast of a human to have been banished to all of these awful, dark lands.

2. The real Beregard died years ago, and his mother Osyra has been propagating this elaborate fantasy to keep the memory of her child alive - as a brave, wild hunter - just what he wanted to be. 

3. Belinda is really a R'hlloran witch from the Far East, who has kidnapped the Baratheon boy and is manipulating him.

4. Beregard was in training to become some sort of assassin for the Baratheons.

5. Whatever the real Beregard is doing out in the world, he's still doing it. The boy sent to the Red Keep is not him. He's a duplicate. Osyra hates the Targaryens; why would she submit to their request so willingly?

6. Beregard isn't out in the world doing something as meaningless as hunting; he must be doing something with meaning. What if he's training to be a general for a second Baratheon rebellion? What if Osyra disowns Boremund and makes Bear the heir, giving him the power as an unknown wildcard in a war against the throne?