Emily Temple compiles a list of literary figures with strange obsessions. Here’s her entry for the German poet and philosopher Friedrich von Schiller:
Friedrich von Schiller kept fruit flies. Rather, he put rotten apples under his desk to inspire him with memories of the orchards of his youth. When he faltered for the right word, he took a quick sniff, and it materialized.
(Portrait of Schiller by Gerhard von Kügelgen, via Wikimedia Commons)