For those who don't know, April 23rd is Impossible Astronaut Day! On April 23rd, 2011, the Doctor Who episode "The Impossible Astronaut" premiered, starting off series 6 with some mind-blowing plot twists and some new monsters, the Silence. The Silence are creatures that you can't remember seeing the second you look away from them. To combat this unusual type of warfare, The Doctor, Amy, Rory, and River draw tally marks on their skin to remind them that they've had an encounter.
To celebrate the day, Whovians drew tally marks on their arms (some even drew on their face) and went about their normal day, pretending like they didn't know where the tally marks came from. Basically, Whovians love having inside jokes that freak people out.
Here are some pictures to see how people celebrated:
This guy went all out...
And of course I had to participate in the fun!
So beware of The Silence
Because you literally never know when they're around you
But if you do happen to see one, just remember to kill it on sight.