Of course, not some stupid grilled cheese sandwich day! Don't be stupid. Get smart. In this age of silly memes and even dumber cheap entertainment. What next? International toilet paper day? A great advancement for the human race, to be sure, but would it deserve such publicity?

This is actually the International Day of Human Space Flight as the postmark above hints. Did you read eagerly sci-fi books when you were a kid, or even older? Jules Vernes, Wells, Azimov, Heinlein, Bradbury, Clarke and many others from the list just too long to read? Space travel has always been the underlying theme of many of their literary works as well as many popular movies and series. 

12th of April was the day when humanity's wildest dream of conquering space finally came true.