I'm reading a book right now (The Overstory) that centers around trees.  In the particular chapter I'm in, the person talked about deciduous trees and my Brain paused to try to remember the "other" kind.  (You know, one drops leaves in cold/winter and the other doesn't.)

The first word that came up was amphibious but I knew that wasn't right (and I giggled at myself) and then I came up with carnivorous and I knew that that also wasn't right and then I started to think about all the things, especially Science related that I used to know pretty well or really well and have now pretty much forgotten... like the word coniferous AHHH there it is!

So yeah, took a while but I got there, but it was a strange feeling and experience let me tell you!