I have a collection of expressions I'll use in place of "goodbye". Many of these expressions came from hip hop songs from the late 80s and early 90s as is the case with a farewell line I've been using for 17 years now. That would be, "I'm out like Buster Douglas".
In 1991, I was a huge fan of The Low End Theory, an album by A Tribe Called Quest. During one track, "Vibes and Stuff", Phife Dawg says "I'm out like Buster Douglas". A huge Mike Tyson fan at the time, I was still stinging from the shocking Buster Douglas knock-out in 1990. In his very next fight, Douglas was knocked out in the 3rd round by Evander Holyfield and Buster never boxed again.
Here's the scene from February 11, 1990 in Tokyo, Japan. Tyson was out like Buster Douglas.