Alanis isn't the only person that doesn't know what irony means. I hear the word misused all the time. In fact, most of the time when I hear it uttered, it is used incorrectly.
One recent example had to do with the Michigan State Spartans playing in the Final Four at Ford Field in Detroit, Michigan. Some talking heads on TV talked about the "irony" of MSU playing in front of what was basically a home crowd, or as close as a team can get to play a Final Four "at home." Gentlemen, that's not irony. That's fitting.
Let's clarify what "irony" means. Webster's Dictionary defines it as:
2 a: the use of words to express something other than and especially the opposite of the literal meaning b: a usually humorous or sardonic literary style or form characterized by irony c: an ironic expression or utteranceIt's a pretty simple word, not hard to understand or use.
3 a (1): incongruity between the actual result of a sequence of events and the normal or expected result (2): an event or result marked by such incongruity b: incongruity between a situation developed in a drama and the accompanying words or actions that is understood by the audience but not by the characters in the play —called also dramatic irony tragic irony
My Science Fiction teacher in high school -- best lit class I ever had, by the way -- hammered the concept of irony into our heads. He loved stories with ironic endings. "Irony is the twist in the story," was how he defined it as he turned his hand from palm upward to palm facing the floor.
One of the first stories we read in that class involved the death of a woman by her husband so that the couple could live together in eternity. The ending wasn't expected. The irony, teacher explained, was that, "He loved her so much he killed her," one of the funniest things any teacher ever said in all my years in school. That is irony.