Board Thread:TV Show Discussion/@comment-28365360-20160502213727/@comment-208.185.154.66-20160503181156

This is one of those theories which has no evidence to support it and no evidence to disprove it. We just don't know enough about the history of Hodor at this point to make any educated guesses at what happened.

My thought is that it is probably something more simple. in S2 Ep2 Old Nan prevented Hodor from fighting and they made a big deal about the kids pushing the issue and her veto'ing it. My bet is that he eventually was involved in some sort of sparing accident with one of the Lordlings that resulted in his slowed intelligence. Likely Ned felt bad about it which is why he kept him around but didn't put him in "fool or Jesters" role like most mentally handicapped people in this world.

That said, who knows for sure at this point. Simple not enough info to go on yet.