3.
It's relative to the highest peak of fun. So when you're bored you tend to think about times when you were not bored, when you're not bored you never think of times when you were bored. So when you're not bored your just happy (not thankful for not being bored) but when you are bored not only are you sad, but you're annoyed because you remember the times you had when you weren't bored.