I knew I'd draw you in with that incredibly fascinating thread title. It just screams: "CLICK ME" doesn't it?
Did you ever have to look up the definition of a word that you've heard used all your life?
I did: "Caveat"
I realized all of a sudden that I had two different meanings of it in my mind. The definition when I read it and when I hear it.
When reading it I always thought it was pronounced: 'Cave Eat' and thought of it like a cave forming under a road until it collapsed. . . so basically something bad that needs fixed before it causes a big problem.
When hearing it I never made the connection that 'kah vee ott' and 'Caveat' were the same word.
I just realised like 2 minutes ago that these were the same word even though I've heard it and seen it used thousands of times. So I just looked up a word that I probably should have known the definition of since I was 8: http://dictionary.reference.com/browse/caveat