Did you hear about this story? UK Scientist Find 'Lost' Darwin Slides.
Apparently, these slides were in a box shoved in a "gloomy" corner and have been overlooked for...150 years! Dr. Howard Falcon-Long (love that name!) "described the feeling of seeing that famous signature as 'a heart in your mouth situation.'" No joke.
Now, you see why you should clean out your closets now and again. It's important for research institutions too. ;)
Sorry, peeps. I couldn't resist.