Glen's story about the okra pod that looked like a snail shell reminds me of
one of my foolish moments.  We had collected some 25 species of Eocene
gastropod fossils from an Alabama roadcut site.  I was sorting them at home
and, as usual, had a group of shells I couldn't quickly identify.  I went
through these, looking through my books and kept coming back to what looked
like a small slipper shell but no ID. Well, I made several attempts to ID
the thing and then something clicked somewhere and I realized I was looking
at half of very modern pistachio shell.  Talk about feeling stupid!