I reach for the (non-existent) downvote button when there is a particularly bad paper on the arxiv.org preprint server.
I've long maintained that Facebook ought to have a “dislike” button (since long before I found LessWrong, and shortly after the “like” button was added), but now I sometimes look for it. (Also, I think I've accidentally used Markdown on Wikipedia.)
In the style of Jeff Foxworthy's "You Might Be A Redneck If..."
If you're waking up and the characters in your dream start asking you to stay asleep a bit longer because they're running on your brain and they don't want to be consigned to oblivion just yet... you might be on LW too much.
Happened to me this morning, it was kinda weird, and I felt kinda sad. In fairness, it might just be my subconscious brain telling me I need to get more damn sleep.
Anyone have similar stories?