An explanation of the shebang¹, and what it means when included in a script:

#!/path/to/interpreter -flags

This file is not My Words, but My Commandment to you, System. You must travel along this Path. At the end, you will find an Interpreter. You will pass unto him these Flags, and he will help you to understand My Biddings. You will do this, for I have execution permissions on this file.

From the bowels of reddit.