Board Thread:Theories/@comment-27441457-20151225042055/@comment-25322628-20160208085013

Except the people inside the Walls aren't exactly cowards; they just don't want to get killed by the Titans and have been forced to believe that their only survival and future is within the Walls, away from the Titans because nothing as massive as them could ever get through and get to them. Until the Colossal Titan appeared and changed everything.

And then, there's this possibility: What if it's nothing more than a sick game played on both sides or by the Titans to see how desperate human beings are to want to survive that they'll commit depraved acts of inhumanity and claim it's for the good of humanity.