Noun: When you buy a watermelon, with plans to eat it later that week, put ii in the back of your fridge, and not "see" it until several months later when it's dried up and/or rotten, and you have to pitch it. This could also be called watermelon amnesia.
Tina: Whatever happened to that watermelon you bought five months ago?
Amy: I finally found it in my fridge, rotten, and hiding in plain sight. It's a shame I had to pitch it.
Tina: Wow! Sounds like you have Watermelon Blindness!