kimbleism
The practice of using a word, phrase, statement, one-liner or action that is so wacky and makes no sense whatsoever but is said or done with such conviction that it becomes utterly believable and appears as nuggets of wisdom.
My friend was so utterly confident when he told me that swimmers never get dehydrated while in water as their bodies automatically absorb the necessary water through osmosis. I almost believed it till I realised it was a kimbleism!