A kook of the day is a kook (a person who thinks or says they can surf but can’t) who does something extremely kooky or embarrassing.
Did you see Sara wipe out on that wave? She was the kook of the day for sure.
January 25th. Jeon Jungkook took a selca and posted it
"Today Jeon Jungkook posted a selca, so we call it kook selca day"