Words whose meaning you misunderstood for a significant amount of time
 

Have you experienced this sometimes? When you go about your life thinking you know the meaning of a certain word or phrase and then you suddenly discover you had it completely wrong the whole time?

My example:
So I used to be convinced that the word 'mezzanine' referred to a certain type or brand of pesticide. The buggly-wuggly on massive attack's album cover is probably what caused me to make the association:
https://upload.wikimedia.org/wikiped..._Mezzanine.png

If anyone doesn't know, this is the real definition:
now you go