It's odd, we were just having this conversation over at KOL not even an hour ago.
I walked into an Enterprise Rent-a-car yesterday and stumbled into a game in progress between the employees. I was amazed and blurted out an "Oh my god, are you guys playing D&D?!" and the players turned as one and leveled a look at me that made my stomach drop.
It was only as the overly excited DM ran up to the counter to help me and chew my ear for a half hour that I realized that he must have been torturing his non-gamer coworkers for about a week and that he just didn't understand or realize that a fairly large chunk of the universe does not, and will not give a crap about your hobbies, no matter how much you try to convince them that they're going to freaking LOVE those green eggs and ham.
I am a gamer. Am I embarrassed by that? No.
BUT, there are a lot of time that I'm embarrassed by other gamers.
...Actually, no. Let me rephrase that. I am a loud and obnoxious person, and I am embarrassed by other loud and obnoxious people who don't know how to reign it in when they are in public; and unfortunately, in the circles that I run in, 95% of those people are gamers.
Sitting in a restaurant, or on a crowded bus, or in the lobby of an Enterprise Rent-a-car, having to listen to someone recount, round for freaking round, and in a booming get-it-to-the-back-row-of-the-auditorium voice, how last week he marched to King Dwarfhammer's castle and murdered 27 orcs and one of them was riding on a dire wolf and he got three crits on the dire wolf, so they decided that meant that he cut off it's head, so then he made its head into a helmet...
I don't want to sit through that conversation under any circumstances; but especially not in a place where it's going to be mistaken for the unmedicated rantings of a mental patient.
Professionally, I travel in a lot of different circles, and a lot of them lean very heavily towards "artsy" or "geeky" so I can usually get away with people knowing my dirty little secret. That being said however, I do not advertise, and I make sure that I keep a separate online presence for the people who don't really know me.
I am not a public figure, but there are times where my job makes me pretend to be one. A lot of what I do relies on a facade that's two parts politician and one part rock star, and having someone google my name and email address and tie me to a hobby they deem as socially unacceptable could be disruptive.
The center piece of my house is the game room. There's a huge, custom built game table that dominates the room. The walls are lined with bookshelves that have a couple of hundred board games and RPGs on them. Most of my work friends have never been past my front door.
I'm not embarrassed about being a gamer, but I know that some things will be easier if people don't know.