"I once had an assistant who foolishly ignored my warnings on engaging with the Fey. Next thing I knew, he was gone in the blink of an eye, and in as much time was brought back. He had gone from a quiet but intelligent fellow to a bumbling, giggling idiot with his head in the clouds. It took ages for the clerics to cure his Feytouch! I had to do my work all by myself! I dismissed him for being so inconsiderate."
-Excerpt from Beyond the Material: Volo's Guide to Extraplanars