Hodor must have been such an easy character to play and write for. "What should Hodor say?" / "How about... Hodor?" / "Perfect!" It doesn't lead to the most dynamic dialogue, but not many actors only have to worry about how many times they say their own name. It's the perfect role for someone like me - very lazy.
If you're a fan of 'Game of Thrones' then you know that he's a fan-favorite character. I've even seen door stops that say "Hodor" on them. That's a very good joke for anyone who has watched the series. If you haven't seen the series then it just looks like the name of an Ikea product. This fan must not have had his doorstop handy, but he was wearing the right shirt at the time. I think we know how this picture went down: "Say Cheese!" / "Hodor!"