There’s a cool article on Quartz explaining the neurological cause of Game of Thrones fan-favorite Hodor saying, well, “Hodor” all the time. It’s an actual condition called expressive aphasia, caused by a lesion in the brain, sometimes caused by a blow to the head or a stroke. The article goes into much more detail, an interesting read for sure. It also makes you wonder if Old Nan dropped him on his head as a child.

BTW, as the author points out for the TV-only fans, his name’s not really Hodor.