WTF does this code do?

This is why you should always use semicolons in JavaScript. Omitting semicolons here turns this:

  var angry = say('Garrrr!')
  
  // what should I say?
  (amIHappy ? happy : angry)()

  var angry = say('Garrrr!')(amIHappy ? happy : angry)()

Most web browsers (if you're running this code in a web browser), will do ASI (automatic semicolon insertion).

http://jsfiddle.net/CxUXh/ works fine in Chrome, changing the console.log to an alert.

Not that I'm advocating omitting semicolons!

Does it return that because `say` isn't defined inside its own function definition, so it evaluates as false?

It doesn't seem to do anything.

Hahaha, nice!

I'm getting a linter.

this is idiotic