5

The correct order of the letters in the English alphabet was discovered, and then lost, by a team of literary professors in Scotland in 1976.

There are seven words in every Gideon's Bible - y'know, the one they stuff in every hotel room - that can't be found in any other bible. If you repeat those seven words to yourself while grasping the doorknob to your room, the door will open to any hotel room in the world. Of course, if you want to control where you're going, you'll need to know the Gideon's Key - one more inserted word, unique to each copy, that acts as an index for each room.